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Karthus Build Guide by Hullos

Middle 2.4 Million Mastery-Lane Karthus Guide-Season 12

Middle 2.4 Million Mastery-Lane Karthus Guide-Season 12

Updated on August 4, 2022
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League of Legends Build Guide Author Hullos Build Guide By Hullos 144 8 507,127 Views 12 Comments
144 8 507,127 Views 12 Comments League of Legends Build Guide Author Hullos Karthus Build Guide By Hullos Updated on August 4, 2022
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Runes: Dark harvest

1 2 3
Domination
Dark Harvest
Taste of Blood
Eyeball Collection
Ultimate Hunter

Precision
Presence of Mind
Last Stand
Bonus:

+9 Adaptive (5.4 AD or 9 AP)
+9 Adaptive (5.4 AD or 9 AP)
+6 Armor

Spells:

1 2 3 4
Mid 1
LoL Summoner Spell: Exhaust

Exhaust

LoL Summoner Spell: Flash

Flash

Ability Order Ability leveling

Threats & Synergies

Threats Synergies
Extreme Major Even Minor Tiny
Show All
None Low Ok Strong Ideal
Extreme Threats
Ideal Synergies
Synergies
Ideal Strong Ok Low None

Champion Build Guide

2.4 Million Mastery-Lane Karthus Guide-Season 12

By Hullos
INTRODUCTION
I play Karthus, a lot of Karthus. I may not be any challenger mid player, I got diamond for a while with Karthus and I was diamond last season but decayed after playing Valorant for 2 months and ended in plat one. I have 2.4 (old MP picture) million mastery points on Karthus and play way too many normal games for my own good. I may not be able to tell you how to get to challenger, but I might be able to tell you how to build and play Karthus.
Regarding Most Recent Buffs and item Changes

MOST RECENT KARTHUS BUFF


Karthus is getting a 3 base armor and + 9 health growth buff. Nothing crazy and honestly would have liked more in the way of damage since that’s all Karthus is good at, but it is something. This might help some ad matchups a bit and maybe the JG clear and the hp at lv 18 is is like having a free ruby crystal, I imagine most assassin matchups will still have little issue one shotting you, but this is still not too bad of a buff.

MOST RECENT ITEMS AND RUNES CHANGES



MASSIVE HEALING, STATS, AND PEN CHANGES
After some testing, this patch hurts. Karthus is a damage-oriented champ so having every champ, especially adc's, becoming harder to kill, makes karthus that much less useful. Along with this patch comes build priority changes. Liandry's Anguish is now more necessary than ever with the health buffs to champs. The same goes for Demonic Embrace even if it got nerffed a bit. This also makes ludens feel worse since all squishy champs now get up to ~16 MR. Anguish at least had a small upside with the health buff, but ludes got no such help.

While the shield nerfs was alright, the healing nerfs sadly and somewhat expectedly did nothing and healing is still just as good, maybe even better. I think anguish is going to be the go-to basically 100% of the time now and demonic will show up now more and with anti-heal not doing as much there will even be room for it.

follow up patch to the durability patch



New patch notes have come out about some furthure item changes. Starting off with the main one, they finally nerfed Liandry's Anguish, it was only a small base damage nerf but with how much damage the passive does, it will sitll be felt a bit.

But in other item news, some of the ap mythics got some changes as well. Crown gets 10 ap, night harvester gets it passive cd lowered by 10 seconds and a bit more ability haste, and rocketbelt gets 4 more magic pen. None of these really matter too much for Karthus. The night harvester changes is kind of interesting and a step in the right direction to it maybe eventually being a good item on Karthus.
Pros and Cons and Quick Tips

Pros


-Versatile builds and play styles
-low skill floor and high ceiling
-great carry potential
-High damage
-Great in team fights

Cons


-quite a few rough match ups
-needs to hit a lot of skill shots
-no mobility
-little utility

Tips to keep in mind when learning Karthus


There is no one best build, no build that you will build 100% of the time. People may try to tell you what build is the only good one but they are almost always wrong. There can be a build you feel most comfortable with and that is fine, but all builds have their uses in certain situations. Karthus is deceptively versatile in builds. I encourage you to play and try different builds. Some of them will surprise you at how well they work.
Your play style will change based on build and lane match up. To play Karthus effectively you will have to learn new play styles e.g( poke, aggressive, safe,). Often you will be switching mid game depending on items, levels, and how strong you are. All to make sure you don't lose a lead by not adjusting play styles. This will also apply to builds as you might have to shift what you are building to go into a fast Zhonya's Hourglass or Void Staff.

Karthus is not always a "just press R champ" there will be games where your Requiem will be almost useless and you will have to play well with Lay Waste and positioning. Same goes with "abusing passive", don't go flashing in every fight. In reality there are few times where you will need to do that. Often you will be playing like a zone/artillery mage.
One of the most important tips is that just starting out, you may feel useless outside of pressing Requiem and Death Defied. A lot of the skills you need for playing lane Karthus are gotten from playing him. I cant tell you how to hit Lay Wastes, you learn by playing. Once you start to get good you can start to duel any lane opponent much easier. Also something important is that different people will find different match ups hard, I find Malzahar to be super easy but you may find it hard. My match up list is not the be all end all. Also depending on rank the match-ups can change considerably.
Summoner Spells
GOOD
One of the two main summoner spells for Karthus mid/top, Though of the two Exhaust is the more popular. As a basic rule I like to follow that works most games is if the lane opponent lacks a good way to escape a trade or all in than this is most likely the better option. This also, opposed to barrier, does offer some kill potential.

GOOD MID
The other of the two main spell though this is basically only taken mid. As opposed to exhaust, this is for opponents that can get out of a trade for free such as Yone. barrier is up more often and is better against quick burst champs on short cooldowns. While it does not offer kill potential it does serve as great bait when you are low and the opponents forgets you have it.

GOOD BOT
If you are going bot you basically always take this. Though if you have a duo and want to be aggressive Exhaust can also be good.

EHHHH... MAYBE
Only taken top lane as not to set yourself even further behind as you already have for picking Karthus top. While not great it can be taken mid though I almost never have found that useful over say Exhaust.

BAD
This is almost never taken unless you feel like going absolutely crazy on your lane opponent. The problem with Ignite is that if you are close enough to use it the Opponent is almost certainly already on top of you and in that case you want exhaust or barrier. Also, in late game, you are almost always in the back line and will find it even harder to use.
Runes and other Options
This is the rune page most player go with and for good reason. While generally not as good in lane as Summon Aery, partially because of healing nerfs this tree has seen, this rune does make it so you will almost for sure do dmg no matter how much you int, as long as you get the DH stacks. Also offers up the just press R play style with ult hunter. If you are starting out on Karthus this is most likely the better pick for you.
This is a lane focused rune page as it offers much better poke in lane and better mana sustain. Though, even with gathering storm, will often feel worse late game. If you need a lead in lane this rune page will be better for getting it but you need to play a bit better to keep the lead.
I will be explaining the whole inspiration tree here as it stays the same basically every game. Starting off, First Strike is a rune that can potentially give karthus a huge amount of gold. But in doing this puts you in a number of disadvantages you would normally not be in. Thus, should only be taken in matchups you feel quite confident it. For the first rune, Magical Footwear, this is just free gold. Once you start ulting for gold as long as you get some assists along the way, these should come pretty fast. Next is Future's Market, this also in essence give you more money, and how it works makes it good for getting power spike items faster. Finally in the first tree is, Cosmic Insight, this is honestly the only good rune of the three options. time warp could be good but since you are basically forced to go tear, you will not have corrupting. For the secondary tree it is domination. This is unusual because karthus would almost never pass up on the precision tree but in this case, you want to because of Ultimate Hunter or Treasure Hunter, if you are going to be give up a lot of good runes for gold, ultimate hunter is just more gold, same for treasure. This also works in the build that will be explained in a later section. As for the other final rune, Eyeball Collection will stack very fast due to how you have to get the gold.
With some testing the rune is good and an option to take for games. There are some deciding factors that I take into account when deciding if I want to take the rune. The main one being how good my ult is in any given game. Things like how many Zhonya's Hourglass's can the enemy team build? Do they have champs like kindred or bard who can make your ult less impactful? Will team fights happen early? Basically, deciding if that ~20 seconds off ult will come in handy. There are other reasons to take this rune though, like if you know you need to become strong fast say against an early game comp. That’s how I feel on the rune though it can also be boiled down to preference.
Its a bunch of free ability haste on the ability that needs it most. Not much to say here. If your ult is crucial against the opposing champs than this is a must.
Many people will argue between witch of the two are better, both are great and help a ton. While Last Stand will often do more dmg, Coup de Grace will allow you to execute low enemy's securing kills. test both out or chose depending on which fits you better. In the end no Karthus rune page will be without one of these.
While I take gathering storm much more often than scorch, scorch is still an option for certain lane where poke is very important. Lanes like akali is where I take scorch sometimes to try to prevent an all in as much as possible. But more often than not, go storm.
This rune is essential for karthus right now. Karthus uses a lot
of mana, so getting a chunk back on takedown is a huge help. The mana regen on ability hit is not too bad either for lane. You will take this EVERY SINGLE GAME on karthus.
This rune is taken if you are using the aery rune line. nice to have as it basically makes sure you don't run out of mana even if you poke a ton.
Ability Haste for free is nice and this rune will still be used though the third part of the rune we don't use all that much.
Easy sustain in lane, this rune grants a surprising amount of healing over the duration of the game. The other two in the tree Cheap Shot and Sudden Impact are either not usable or not used enough to consider running. unless you are in jg.
Pick your poison, all grant you 30 AP, just figure out which one you are going to stack the fastest or most reliably.
ITEM AND BUILDS

STARTING ITEMS


ALSO SEE THE STARTING OUT PORTION BELOW THIS SECTION FOR A QUICK OVERVIEW OF THE RECOMENDED STARTING OUT BUILD.



Currently not good
This item right now is in a weird spot, the item itself feels bad to start with, but now the item it buidls into is not too bad. It sucks to start with but if the build needs mana then so be it.

Good
This item is good for mana and helps you be aggressive in lane, Though might present some mana issues if you are not carful. If you starts a mana mythic this is the better choice.

SITUATIONALLY GOOD
While I don't take it often first item, it is still good. I buy it when I am already ahead or feel strong. But more often in the ludens build. If you want to start it over Doran's Ring, you can, just be extra carful with mana.

SITUATIONALLY GOOD
When you want the aery rune but still want sustain this can be great. Also is better with the loss of base healing on rav hunter. You lose a bit of all in pressure but helps with poke over time.

MYTHIC ITEMS


BAD CURRENTLY
The item is cool in theory, but with the lack of mana, it become a hard sell. Having to build tear right now is a detriment, so that kills the item almost singlehandedly. also Luden's Tempest offers mana and pen even if its bust is a bit worse.

GOOD
This item is the go to item for most players. The amount of damage its burn effect can do on karthus is just ridiculous. Not to mention the extra damage vs tanks. this plus the mana and ability haste, its just a perfect item for karthus.

BAD CURRENTLY
This item did see some experimentation at first but since has fallen completely out of favor. With a change that lowers the omnivamp and removes the pen the item only became less useful on Karthus. Until the item sees changes do not take this item.

EHHH... MAYBE FOR FUN
This item is kinda cool but lacks a large enough amount of ability haste and reliable DMG. While it does give you AP for every legendary it still cant compare to the DMG of even Luden's Tempest or any other mythic for that matter. The passive, while cool, is unreliable and only lasts 1.5 seconds so with low ability haste around 1 Lay Waste and that's IF you hit the active. Though it does not need to take tear witch is a up side.

SITUATIONALLY GOOD
This item did seen some changes in the form of a CD reduction mechanic on Echo. This is a decent buff for the item on Karthus as his E Defile can reduce the CD fast. In tandem with the anguish changes this item is, for now, is a solid option against low MR teams. Matched with an early void staff or soul stealer early can make this item destroy squishy targets.

MEME BUT BAD.... STILL FUN THOUGH
This item started to appear as another option for Karthus for a bit as a tank route but the item has been confirmed as bad. Though in my testing it is not unplayable if the team needs a tank. You will still do decent late game DMG but in early and mid game you rely on your team to deal DMG so make sure you have some before you build this. I think this build is still a meme build but can be fun to build and may be viable in the future.

LGENDARY ITEMS


GOOD
Basically a legendary item. I recommend getting these right after or before mythic item. Though I often get them before any mythic components if I have the gold, as 18 flat pen will be a lot more dmg then 40 ap on karthus. Its a great way to try to get a lead in lane and the movement speed is just icing on the cake.

A decent option
While you do still have to build tear, the item it builds into is actually decent now. The item is now only 2600 gold. For that cheap: 80 ap, spme hp, ability haste, more mana you will ever need ,and some decent healing is a good deal. I would still only take it into a team where they have heavy poke, but it does its job well.

SITUALTIONALLY GOOD
If the Dark Seal you bought ends up getting some good stacks, there is really no reason not to upgrade it. on the ludens build it even gives a cheap legendary item for 5 free flat pen. Though late game you will die more so you will most likely end up selling it.

GOOD
This item is really good for karthus and fills one role perfectly. The item you get if anti-heal is not necessary. This item gives a nice chunk of hp at 450 with do respectable ap numbers at ~70+. The burn is also really solid and can provides some crazy damage charts with anguish. While you often get it somewhat late in the build, it is still a great item.

SITUALTIONALLY GOOD
I mean yeah, the item is great for teams that heal. You build it if they heal, don't if they don't. I like to think of the number of healing reduced as extra damage because it kind of is.

KINDA DECENT BUT HAS TOUGH COMPETITION
This item finally has a combo item again, this time with Horizon Focus.But honestly the item combo sucks. What this items does do though is if you have trouble doing damage in a game why not perma slow the entire enemmy team. It is good not all the time but it can work well.

NOT GREAT
This item sucks on karthus, but when you buy a Rylai's Crystal Scepter with it, it might be worth the 5600 gold of the two. The main issue is its competing with the Void Staff + Rabadon's Deathcap combo. While the damage is for sure lower from the scepter + focus, it offers up the slow and 500 HP extra. One other thing is, on its own Horizon Focus sucks on karthus and the scepter is just okay. But void and deathcap are both amazing items on their own. So there is that point in time where you will only have scepter and feel pretty weak. And often games can end before you get the other item and you will wish you had void or deathcap.

GOOD
This item is a must in many games, in rare cases even first item. The component Seeker's Armguard did get a nerf a bit ago but it is still good to build early. hourglass is too good to pass up as an item as a whole.

SITUATIONALLY GOOD
This item is not as good for karthus as hourglass, but it is better than you might think. The MR item component is a solid buy into AP lanes like LeBlanc and can often save the lane. The item itself is not too bad either, bit more AP the hourglass with the same other stats but with MR. The spell shield feels better than you might think as it allows karthus to poke and get into position much better, and on karthus those are key.

SITUATIONALLY GOOD
This item is weird. It is a huge power spike no mater when you get it. There is one problem though. When you start to buy the item, if it takes too long, you could lose your lead or fall behind due to how long it takes to get it. So consider buying it with care, I recommend going for void or GW before getting this item if they are needed.

GOOD
The it is an anti-tank item... but who cares because it also basically gives you true damage vs squishy targets as well with boots. It only gets better in the ludens build so much so where you often build it second.


Builds - lots of words




[*] Anguish anti-tank DPS

Due to the nature of this build you will want to be in fights longer to maximize dmg, thus aery often does better in this case. Aery also can often out dmg Dark Harvest also better at getting you ahead to the Liandry's Anguish power spike. Dark Harvest can be taken still but I prefer aery most times with this build.

Playing lane


One major plus of this build is the fact that you don't get Tear of the Goddess due to manaflow and the mana from anguish. This means that getting Doran's Ring and having aery means you gave a ton of early pressure for poke. While you are still prone to assassins, if you poke properly, you can prevent the all in. The core of the build is Liandry's Anguish and Demonic Embrace, the two items together grants tons of over time dmg that if play properly can end up doing upwards of 25k dmg together over a game. Then paired with hourglass means you can survive dives and stay alive longer plus becoming even more tanky with demonic' s HP. Then finally with the anguish passive and a potential Void Staff you can deal with tanks great, you might even have room for a deathcap if you don't need anti heal. The main weakness though is the lack of sustain. Doran's Ring does a serviceable job in lane but late game it can become a bit problematic HP wise. That is why it is even more necessary to play back and safe to maximize dmg till the time is right to die.

When to run this build


This build is now the best build for lane and JG (jg taking DH though). It works in any scenario against any team. Only Luden's Tempest when into an entire no tank team can outperform it. The lots of dmg along with antitank mana and solid ability haste makes this build the way to go.



[*] Ludens Full Pen

THIS BUILD FEELS QUITE A BIT WORSE SINCE THE DURABILITY PATCH, I RECOMEND GOING ANGUISH UNTIL SOMETHNG CHANGES
Of course when you hear full pen you are taking Dark Harvest. Though along with all of the basic runes you will want to take the ability haste passive rune as the build only gets the 20 from ludens and is stuck on that till you get Zhonya's Hourglass.

Playing lane


This build in lane plays aggressive as your main goal is to get a lead, ask for ganks and play to your lead. Of course Doran's Ring is a must in any aggressive lane. On first back you have a few options, first, Dark Seal is a great first back with other components towards Lost Chapter. but if you can buy the full chapter don't let the dare seal get in the way of that. You can take Barrier but overall Exhaust is going to be more helpful to get kills and since you take this into a team that is all squishy the likely hood that one opponent will get fed and and needs to be exhausted is high. If you don't get a lead in lane make sure you keep trying to stack the Mejai's Soulstealer as Requiem is great at getting assists. In order for this build to work best the more stacks the better. Going into mid game is when this build shines, if you successfully get fed you can pop any opponent as the backline mage karthus always wanted to be. That also means that the run in and int playstyle will not work here as stacks are very important. Of course when the time come you might have to int but this build with do it much less than other builds.

When to run this build


As is said before, this build works best into no tank teams. This is the same as Night Harvester, The only difference is playstyle preference. If you can play like a backline mage effectively then this build with over all be better. Also its best to take this into a lane opponent you are confident you can win against. otherwise its best to go with anguish because that way you are useful no matter what even if you lose lane.

[*] First Strike Tear Snowball

This build is quite uncommon but the point of it is to gain a massive item/gold advantage. This is done by basically ulting off cooldown to proc first strike. Things like Ultimate Hunter or Treasure Hunter are here to make that work better. this with the other gold gain runes such as Future's Market will get you full build in record time if it can be pulled off. Not having Presence of Mind will hurt, but that is made up for in the build.

Playing lane


This is the one build right now that builds Tear of the Goddess basically every game. This makes up for the lack of Presence of Mind. Normally this would hurt a bit more, but by playing first strike you are already giving up lane phase... Kind of. If you play this in a matchup you are confident it you can mitigate this and potentially still get even further ahead. Also, by confident, I don’t mean winning. I mean a lane where you know the matchup to the point where you can constantly avoid death. IF the matchup does happen to be winning, all the better. For first item, its Liandry's Anguish. The item path is also basically the same as any the normal anguish build just with tear. But here prioritizing Void Staff and Rabadon's Deathcap are quite important as those are the most snowball items. A Shadowflame can also do well against certain teams. But at the end of the day, if you need hourglass, get it. In lane it is very simple, farm and live. You need to have good farm to support this build as if you fall behind on levels so will your ult level. If you can kill the opposing lanner, that’s good, but risks should be avoided. As long as you don’t fall behind, you are ahead. Due to taking worse runes and tear, you are a good bit weaker in lane so it might be difficult at time to stay even. Finally, the most important step. Once you hit level 6, start ulting. While the free gold is nice, here it is important to get an assist or two because you have two take down stacking runes. The faster you stack the hunter runes the better. With Liandry's Anguish ability haste and maybe ult hunter, your ult should be on a pretty low cooldown. I recommend ulting almost off cooldown till close to lv 16 or when team fights become too important to not have ult.

When to run this build


I mentioned it a bit before, but this build works best if you know the matchup well. You want to have the least chance of falling behind as possible due to the disadvantages you have with this build. It also helps if the enemy jg is a hard farming jg so you can avoid ganks/dives.



BUILDS BELOW THIS LINE ARE EITHER MEME OR NOT CURRENTLY VIABLE





[*] Night harvester tear

The rune page to take is the classic Dark Harvest with precision secondary. You will have Archangel's Staff but even so Presence of Mind is still very helpful as in long fight you will still run out of mana. It also keeps you in lane longer mana wise. Of course the DH proc with Night Harvester is disgusting and can pop ADC's if they are not dead already. The goal for each fight with this build is to kill the squishy targets and that's what this rune page does.

Playing lane


While this is the big DMG build the start of the lane phase will be mostly passive on your part. This is because you are forced to start tear and lose a majority of pressure in lane. Though killing the opponent is not out of the question with some good poke before a fight. At first back hopefully you can buy a Hextech Alternator, this item is great and gives a large spike in kill potential. Keep in mind that you are still squishy and have low HP. This means that while you will mostly be taking Barrier or Exhaust without extra HP from Doran's Ring and the ideal first back item also giving no HP most lane opponents can kill you in the 1v1 if you don't poke well before the engage. You will start to realize that poke is a large part of this build as the passive of Night Harvester provides so much of it. Not only are you just as squishy as before the new items but most other champs also got more DMG. But the same applies to Karthus, this means that it is more important than ever to play like and artillery mage for as long as possible till you actually need to die, of course make sure you die in a useful place. This makes sure that you get the max amount of damage as possible. Abuse the passive of Night Harvester and its movement speed to reposition after a procing it.

When to run this build


This build is nice but even so mainly is only taken when the opponents team has no tanks. It can obliterate squishy targets but fails to do meaningful dmg vs tanks and bruisers. Though in ADC this build becomes a bit more possible as you can guarantee fighting one squishy target.


[*] RiftMaker Sustain - for fun build

Dark Harvest in an attempt to make up for the loss in DMG with this build and Ravenous Hunter to add on more omnivamp. Just the basic rune page lines up well though sorcery could be taken to use Absolute Focus and another dmg amp rune although Manaflow Band would most likely be useful as karthus might need more mana than tear can provide at some points with this build.

Playing lane


This build in fact has less DMG than most previous karthus builds with old items and on top of that less healing even with the omnivamp from Riftmaker. While it can be nice in lane as a first back item Leeching Leer the lack of ability haste makes it have a TON less DPS than other builds. This means that other builds due to increased DMG might out heal this build just with Ravenous Hunter. While the passive is cool, surviving to have it at max stacks is difficult (that's part of the reason demonic embrace is part of the build so the burn keeps you in combat). Even the true damage is lack luster without the dmg to back it up with such low ability haste. You could take Cosmic Drive to mend that problem and get some MS but to build another item just to make ends meet is not ideal. The upsides for this build is that in lane it is the safest build with the most sustain. Thus being the safest lane you can take Teleport and not get killed. Also with the Liandry's Anguish nerf it now has higher %pen for later in the game, but it still takes forever. The last good thing I can think of is that this item would feel solid into assassins and other bad matchups like Vladimir. Beyond that this build will be mediocre until maybe a tested tank karthus comes to fruition.

When to run this build


This can be taken into tanks but even then Liandry's Anguish is still better. But the main thing to take this item into is into unfavorable matchups like I said Vladimir and Kassadin. The build helps you survive into assassins matchups but does not help you deal DMG later, you will be better off building Seeker's Armguard.
Just Starting Out Quick Guide
When I just starting out on Karthus, all of this information can get a bit overwhelming. So this section is going to summarize what I recommend to take when starting out on karthus for items, runes, and a bit of playstyle.

ITEMS


First Item

In terms of starting items, Doran's Ring is best to start when new to karthus. Dark Seal is an option once you get some experience. for first complete item, while I also believe the Luden's Tempest build is good, the aguish build will always be viable compared to luden's only sometimes. You can take anguish into any team and find success, so starting out on Karthus I recommend that you always go with this build path. Generally you finish boots right after this item.

Second and Third Item

Second item has quite a few options but for simplicities sake, I am going to narrow it down to just two options. Starting with Zhonya's Hourglass, in most games you can feel if you will need this item sooner or later, either way you will be getting it. If you are getting ran at by the enemy assassins or frontline, and they have the ability to kill you. You might want hourglass... obviously. Void Staff is the other option. While hourglass offer mostly defensive states, void is all offensive. Void is one of the most important item for karthus. While it may seem like a anti-tank item, it also performs very solid vs anything. If you feel safe getting into position for fights, then this will be the better option. Usually you go 3rd item what you did not pick for 2nd item, but that can be changed depending on the need for say grievous wounds or if you don't need hourglass.

Forth Item

Assuming there is no need for GW, deathcap will almost always fall here. The only way this changes is if in a game you feel no need to go hourglass at all, then this could be third. Around this time you will have a good amount of ap for deathcap to work with and have the magic pen from void staff, causing a huge spike in damage.

fifth Item... Kinda

The last item will almost always be one of these two items. If you needed gw in the game then you probably built it earlier and deathcap ends up last. But in the case you don't need anti-heal, Demonic Embrace become the best final item option as it offers a very solid amount of damage with its burn, along with some nice defensive stats. you could build demonic instead of hourglass as a defensive item. While it may not have the stasis active, it does offer a whole lot more damage then hourglass and the hp is very helpful if you are getting dove. Both of these items can kind of be built at almost any point after mythic.

Uhhh.. Shadowflame

This item complicates the simplicity of this section kind of. Shadowflame can often find a place in builds now and makes build paths weird so here is a quick rundown. This item can either be built with void staff, replace void staff, or not build it at all. if the enemy team has a mix of both tanks and non-tanks with some MR potentially of both, both Void Staff and Shadowflame could be gotten usually with shadowflame first. But if the enemy team has no tanks than shadowflame can be gotten alone and usually second item. But if the enemy team has more than 3 tanks/bruisers than shadowflame will not be an effective item. usually, it is a simple case of take one or the other, but in the case where you could build both, you have to decide if there are other items that are needed and will help more than just more magic pen. if the game will need anti heal or you need an hourglass to play the game than you might end up kicking shadowflame out of the build. But at this point it is up to personal play style and preference.

RUNES


Main tree

I'm going to be honest, I love the Summon Aery, sometimes more than dark harvest. But when starting on Karthus, you will mostly likely suck like I did and heavily rely on ult damage. Dark Harvest makes that playstyle much more effective. This also gives you access to Ultimate Hunter so you can ult more. Also the page is more beginner friendly as you get healing access, where as aery does not.

Secondary Tree

The precision tree is in every Karthus rune page with basically no exceptions. Presence of Mind provides necessary mana help and the solid damage of Last Stand. Now some people will tell you to go Coup de Grace, but starting out you will die a good amount most likely. So you will get much more value out of Last Stand.

A BIT ABOUT PLAYSTYLE

While I do not like the run in and die playstyle, starting out with it is a great way to figure out if you like it and get an idea of good times to int into the enemy team. To maximize damage with Karthus it take a bit of getting to know the positioning and kitting required. A lot of the skill required for Karthus beyond hitting skill shots is positioning and kitting. Its almost as if you are playing ADC with a suicide button. I found that ADC players can often be good at Karthus positioning and kitting but find the skill shots difficult. I recommend that you start out playing Karthus looking for times to run in and die, then slowly transition into a back line karthus who knows when to run in and die. Over time you should die less and less as karthus.
Other lanes - ADC - Top
TOP LANE KARTHUS


Top lane is the least played role for Karthus, that he can be played in, and for a few reasons. Now more than ever, with ROA gone, top lane becomes more difficult to play. Even if you do take the new Leeching Leer you still will not have the DMG needed to play late game. Even with that item, without Barrier or Exhaust you still might get destroyed if you don't position perfectly. Not to mention most likely you will be fighting some heavy engage bruiser that Karthus struggles so much against. With Tanks, being Karthus's best top lane matchup most times, becoming stronger, them now being able to kill you, that only leaves ranged top lanners as a safe pick to play karthus into. At the end of the day never pick karthus top blind.

ADC KARTHUS

ADC Karthus on the other hand is almost if not just as viable as mid Karthus. Having a support can solve a lot of problems for Karthus and help him make use of early game Lay Waste damage. Though the supports that go well with Karthus are limited, most of them are listed in the synergies tab, they work incredibly. The average shield/heal Support like Lulu is far from the best choice to run with Karthus. But any engage support will work wonders, the best being Leona, Thresh and Nautilus. Most of the time assuming you have a good support, you will porably be taking Liandry's Anguish as with Lost Chapter you can still play agro. Very rarely will you be playing safe in bot lane unless they pick Lucian Leona or something even more agro than your lane. Starting the new Tear of the Goddess means that even with an aggressive support you may find it more difficult to dominate bot lane thus a mana mythic is necessary to start Doran's Ring. There is also the problem that since you are behind on levels and Karthus relies heavily on ability damage you will do slightly less damages than normal.
The late game plan

Pointers on playing late game


Karthus is often seen as a late game champion, but he is not as strong late as you many think. By the time late game rolls around yes you may have 1000 AP, depending on the build, but everyone in the game will almost certainly have a way to survive your Requiem. Weather that be a Zhonya's Hourglass of their own, the supports heals/shields are just as strong as Requiem or they are just a lot more tanky than mid game. Not to mention the countless other ability's. Then at that point in the game everyone else will also be able to one shot you, so it becomes harder to get the most damage. You will start to see that unless you play like a god, you will almost never have enough damage to carry hyper late game as it becomes harder to get the damage off. Keep this in mind going into the next point.

Late game means that inevitably, there will be a lot of team fights. In team fights too many new Karthus players think the right play is always run in like a madman with Defile on and die, this is not the correct play style for late game. Yes there will be times where that is the correct play, but it does not happen often and most certainly not every team fight. I cant really describe when to flash in and die, but a lot of factors come into play, to name a few: has someone else engaged? How many people are close together? Can the team follow up? Can the enemy team get away? Do you have Zhonya's Hourglass up? Instead of going for the all in play all the time, play more like an artillery mage to maximize you dmg and act like a final line of defense for the ADC. Although running in and dying is a great way to learn the correct times to do it.

While in mid game you may have been able to kill anyone you wanted, especially when you are strong, but in late game prioritizing the correct targets is essential. Even if you are late game you will do meaningless dmg to the full tank Dr. Mundo. Since you play like and artillery mage you can aim for the ADC, or other high dmg targets, and with Wall of Pain potentially catch them out. Even when you flash in make sure you are going for the highest threat target. This should be done at all points in the game but becomes even more crucial at late game.
A Few Cool clips I had Laying Around

League of Legends Champions:

Teamfight Tactics Guide