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Karthus Build Guide by Hullos

Middle 2.2 Million Mastery - New Items - Lane Karthus Guide - Patc

By Hullos | Updated on October 17, 2020
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Runes: Dark harvest

1 2
Dark Harvest
Taste of Blood
Eyeball Collection
Ravenous Hunter

Presence of Mind
Last Stand

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


1 2 3 4
Mid 1
LoL Summoner Spell: Barrier


LoL Summoner Spell: Flash


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Jungle Role
Ranked #26 in
Jungle Role
Win 51%
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Ability Order Ability leveling

Threats & Synergies

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Extreme Threats
Ideal Synergies

Champion Build Guide

2.2 Million Mastery - New Items - Lane Karthus Guide - Patc

By Hullos
I play Karthus, a lot of Karthus. I am no challenger mid player, I got diamond 4 last season with 256 games on Karthus. I was diamond this season but decayed after playing Valorant for 2 months and sit in plat one currently. I have 2.2 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 Recent Nerfs and item Changes Back to Top


As for the nerf to Karthus in the most recent patch, it was a simple 2.88 armor nerf aimed at ADC Karthus. While it was small, the nerf can be slightly impactful over time and in the early game. The jg clear also becomes a tad bit less healthy as well as mid matchup's like Zed and Talon become more dangerous. The nerf will most likely not affect WR but will be noticeable.


The new items upon first look seem great for Karthus, though it also looks like the build maybe become very confusing. I will update the guide slowly with a new section for the new items, though even I cant predict the perfect build right away. The new runes also throw a whole other layer to look at and may impact the build heavily. Expect changes to the guide sometime soon as I add section for each item. LOOK IN THE NEW ITEM THOUGHS SECTION.
Pros and Cons and Quick Tips Back to Top


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


-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 just 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 like the Hextech GLP-800 surprised me with its uses.
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. 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 and 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.
Runes and other Options Back to Top
This is the go to rune for your damage centered build, this is most often what you will be using.
Aery is used in only a few builds and mostly for poke and a safe lane phase as well as scaling. But also to grant access to the mana runes for no mana item builds and Tear of the Goddess builds.
If you are taking the Dark Harvest runes then this is a must have, as it provides an insane amount of healing and sustain. Ultimate Hunter is a bait and is almost never used.
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.
This is a rune that will change game to game. Gathering Storm is the clear option for scaling into late and will be the pick if you see the game going past 25 minutes. Scorch is for the lane bully, if you are against almost any melee champ this rune can be very helpful in order to prevent engages with poke, assuming you can poke them.
This rune will almost always be the second pick in the precision rune tree. Even when building mana items Karthus will often need more mana thus Presence of Mind solves that problem. It is also a huge help to the Tear of the Goddess builds granting more AP. Presence of Mind is also the center piece rune for no mana item builds along with Manaflow Band.
This rune is used in no mana item builds and is basically the only usable rune in the tree for Karthus unless into an AP assassin then consider Nullifying Orb
This is again an easy choice as in any build using the sorcery tree it is most likely a no mana item or tear build, both of witch could use some CDR
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.
Pick your poison, all grant you 30 AP, just figure out which one you are going to stack the fastest or most reliably.
Items and Builds Back to Top
The main item for mages, and while this item is very good on Karthus for just doing lots of damage we have other options as well. This item grants mana damage and gets you to the minimum 20% CDR necessary for Karthus. You will be taking Dark Harvest with this item almost every time.
This item on paper seems insane on Karthus, and it is good, it is not as good as people lay it out to be, at least not on its own. This item is for when you are going to play safe and sustain in lane. But even though it grants HP Health and mana, it grants no CDR and not enough dmg. That's why this item is almost always paired with Archangel's Staff this item fixes all the problems of ROA. The only downside being it delays the power spike so the build is only used when you know you will get to late game.
This item is often paired with Rod of Ages, but can be build on its own to hit a smaller power spike earlier, often allowing you to build Liandry's Torment second item.
This item is incredibly strong on Karthus and would be put into almost any build, the only thing stopping it being it offers no CDR and no mana. but many builds such as Archangel's Staff rush and the no mana item build seek to solve those problems to use this item, that's how good it it.
basically the only boot you will ever buy unless you are going the tank-ish build. Great magic pen and a great early buy.
This item is built in most builds in one way or another as magic penetration is very good. One key thing is that if the enemy team does not have heavy healing, it it a better idea just to keep the Oblivion Orb and go to the next item.
Obviously a great item, you build it almost every game in almost every build. The item's synergy with Defile is just great as well as you can throw a Lay Waste right before you activate this item and it will go off when you are in stasis. Of course preventing people from diving on top of you is always great. This item can be build at any point in a build depending on how badly its needed.
This item is good into certain teams and when in combination with Liandry's Torment can be quite devastating for catching people out or in a team fight. Though I would only recomend against teams with low mobility, and at least a tank or two to get value out of the item otherwise its better to just go into Void Staff or Rabadon's Deathcap.
This item is of course the big damage item, and will be in almost every build even if its replacing boots. Though many players get the item too early, this is a late game item and should only be bought no earlier than 4th item. or else you risk losing your lead or falling behind further as its benefits are less are less the faster you get it.
This item is amazing and built again in almost every build. The only time this is not a good item is if the enemy team has no tanks or even bruisers.
I build the item very rarely and only if the spell shield will be benificail. In almost all other cases Abyssal Mask is better.
This item is used most often in hyper late game to replace boots as your sixth item. The item grants movement speed to compensate for boots and a nice passive to get out or get in to a fight, or just to pop the ADC. Solid item but almost never build other than 6th item.
This item has recently risen in popularity, it has its upsides in certain match ups and can help you dominate a lane even more with better engage. The active is also nice in team fights if you can land it on multiple targets. It would only be built to replace Luden's Echo but works well.
Both are somewhat meme items but do have their uses. Frozen Heart can be built in with Archangel's Staff for the clean 40% CDR and Sunfire Cape while you cant proc the passive, it is the best armor item for Karthus that offers HP.

Builds - lots of words

[*] No mana item build

I have mentioned this build many time so far in the guide, the reason being I believe it is one of the best and most consistent builds, while still being versatile. The name makes it obvious but you don't build a single mana item beyond occasionally Dark Seal. The mana all comes from runes like Presence of Mind and Manaflow Band. then in order to deal with CDR you take Transcendence and the 1-10% CDR rune. With mana and CDR covered you can build Oblivion Orb, Sorcerer's Shoes into Liandry's Torment. these three items create a massive amount of power that spikes faster than Tear of the Goddess for the same gold and keeps kill potential in lane with double pen items. The power though does not fall off and only opens paths for almost any other item needed. this build allows for you to get to necessary items like Zhonya's Hourglass or Void Staff faster. You have the option between Barrier and Exhaust depending on lane opponent.
The rune page you will be using is the second rune page on this guide with Summon Aery, making any personal changes depending on match up. this of course is used for the CDR and mana but also grants a large amount of poke for tough match ups with Summon Aery

Playing lane

Corrupting Potion is the main starting item, or Dark Seal, Refillable Potion. This start mends the lack of sustain the build has health wise. with Ravenous Hunter out you need to start this in order to stay in lane and out poke the opponent. That's how you play lane phase for this build, poke until they cannot engage or till you can engage to win the 1v1. mana early can at times be hard to manage but that becomes better the more you play Karthus and the better you become at farming. DON'T JUST SPAM Lay Waste ON THE WAVE EARLY. punish the opponent for walking up to farm and if they don't need to walk up to farm keep a watch for misplays in positioning, you may be good at poking opponents down but a Wall of Pain with a few Lay Waste's is very possible. With this build once you get ahead you can start to be more aggressive with mana once the runes get stacked, thus playing more aggressively, throwing more Lay Waste's at the opponent, hard shoving or keeping the opponent off the wave.

When to run this build

This build is good against everything to some degree, the main thing this build should not be used against is easy match ups. if you are super confident in lane that you can kill the enemy champion this build is not ideal, but since Karthus does have a lot of bad and even match ups this build exists.

[*] Classic DH luden's

Speaking of ideal verses favorable match ups, this is the build. The items them selves don't look all too different but the runes make all the difference along with Luden's Echo. With this build you aim to get as strong in lane as fast as possible, even if you die to get the kill, you turn into a weird looking burst artillery mage. with features of both. with Luden's Echo covering CDR and mana along with Presence of Mind, and Ravenous Hunter with Taste of Blood covering sustain you have all the pieces to need in one item. This build will suffer when against lots of tanks as you may not have the HP or defensive items to live verses them or the damage to kill them, usually you will end up lacking one or the other. But what it does do is one shot the squishy targets and put them to basically half hp at all times with Requiem if you get strong. This build is high risk high reward and creates the Karthus stereotype where he only need to press R.
The rune page you will be using is the first rune page on this guide with Dark Harvest, This is big damage, the pop the enemy ADC in one Lay Waste rune. Aggressive plays and 1v1's are the name of the game with this rune page.

Playing lane

Starting with Doran's Ring you can immediately start bullying your lane opponent with Lay Waste assuming you took this build into a winning match up. Their CD's will often be much higher than yours enabling you to punish for any missed skill shots with Wall of Pain. This only get better as lane goes on as you get more mana And eventual they will not even be able to stay under tower from the barrage of Lay Waste's. The main thing to worry about is of course the jungler, as if you play aggressive as an immobile mage you are bound to get ganked. Depending on the enemy JG, if they don't have a good gap closer and with a good dodge or two of a skill shot a 2v1 is not hard. Just target the likely not full health Jungler as they approach with Lay Waste and you can easily finish them off by the time they get to you. Make sure to kite away between Lay Waste's as that is one of the most important skills on Karthus. This may be the big damage low brain power build but do not fall into the trap that is Flash inting. Many new Karthus players Flash in to "abuse" passive but proceed to miss everything and die. Over time you will start to see the correct time to Flash in. The most often time to do it is when the opponent is doing baron and you need to stop it. Play like an artillery mage for most of fights until the time is right to go in with Defile on. you are back line but still you should die before the ADC unless they are useless. most likely take Exhaust allowing easier 2v1 and better kill potential with the slow.

When to run this build

I said this before but run this into any wining match up or squishy enemy team. This build is also the best to start with as a new Karthus player. simple play style and still useful late even when behind. This build can also be altered to an extent to work decently in most cases.

[*] Scaling late game build

This build is the most simple to play as it revolves around playing safe and farming for late. The main two items being Rod of Ages and Archangel's Staff and getting them stacked. Of course Karthus stacks them fast but even so the power spike is still late. Of course you can go into any item after the first two as well, making it versatile. You can use almost any kind of rune page and can play how you want late game as long as you play safe early. This build makes killing potential in lane almost zero with first items being Tear of the Goddess and Catalyst of Aeons. With no mana problems you can farm forever you will and probably take Teleport for a better scaling experience. This build has the highest AP of all the builds for late game but the worst early even early-mid game out of any of them.
Both rune pages can work for this build, both provide Presence of Mind. The main difference being do you want more sustain and some late game burst of Dark Harvest rune page or the poke and scaling of the Summon Aery rune page. Honestly this is based on preference and what you are more comfortable with.

Playing lane

The most simple lane phase to play, farm and play back. The likelihood of you killing you opponent is very low and the champions that you play this build into you will not want to try to kill the opponent as it will not end well. Ad for starting items, it depends of what rune page you took, if you took Ravenous Hunter then Doran's Ring is the best option. If you did not take it then Corrupting Potion is most likely the pick. A jungle gank can help you get to late game faster as can a lucky Requiem so keep watch for them at all times. This build will out scale or allow you to scale with them so not dying in laneing phase is essential.

When to run this build

As I said before, this is for out scaling or scaling with the lane opponent namely the two big problems being Kassadin and Vladimir two very hard match ups but this build gives you a chance. other times that you can build this is when you don't have much kill potential on either side of the lane such as Ryze.



This is the first item most people look at for Karthus out of the new items. While yes this presents a strong case, it is not the only potential mythic item to build. But looking at This item it seems to have a ton to give. Starting off is the items it builds off of, is the new Catalyst of Aeons, it now gives AP, HP and Omni Vamp. This is a fantastic item that gives everything you could want and is amazing for just a component for the same price as Lost Chapter. Then we see the item itself, in addition to buffed stats of the catalyst it now also grants 15 ability haste and a passive that give more damage and converts some to true damage. On top of all that give legendary items 5% penetration. This is a crazy item and offers everything Karthus could ever want and can be build in almost any scenario. Its hard to believe that any mythic item can compete but there is one.


This is the only item for Karthus that can hold its own for the mythic spot against the folly. This item offers the same amount of AP but that's the only similarity the two share. Anguish offers more ability haste with 25 base and 5 additional for each legendary item. Then grants the classic %HP burn but with an extra %MR shred over time up to 25%. On top of this the item also give 600 mana making it go better with the tear items. This item in theory has more DPS than the Folly but I will add a section comparing the two items further down.


This item is the only other item that you would even take into consideration. The item offers some decent stats similar AP, 600 mana, some flat pen, a passive giving flat pen to other legendary items, the same classic Luden's passive and some ability haste to round it out. The item though does not fit karthus as the burst passive is meant for single target and the flat pen for killing ADC's. While Karthus can and does do that, he also needs to kills tanks and bruisers, of which %pen will do much better and still do well against low MR targets. The item, while matching in stats, is lacking in the good passive department. This item I only see being built when the enemy team has literally no tank or even bruiser.

LEGENDARY ITEMS (important only)


The new Oblivion Orb and Morellonomicon are now literally only for grievous wounds (GR), they no longer offer flat pen so thus they will no longer be built early as a component. Though something good to come out of it is that the orb now has GR and only costs 800 gold. with GW being buffed it might be used more often and not only in Dr. Mundo or Vladimir and such.


This item now has no CDR/HASTE and no shield active, though it now offers more mana AP and costs less. While I have not tested if it take longer or shorter to charge but it is now just a huge amount of AP item.


Zhonya's Hourglass costs 400 less but gives less ap. Rylai's Crystal Scepter cost 100 more but offers 50 more hp. Rabadon's Deathcap cost 200 more and give 10% less extra ap. Void Staff costs 150 less but offers 5 less ap. Banshee's Veil costs 500 less offers less AP less MR but the passive CD is down to 30 seconds.



They are the two best mythic items to choses from and both are very good. Though I believe the folly will come out ahead and be used more. The omni vamp of the folly is incredibly strong and versatile and the true dmg and %pen makes it still a good option vs tanks. The new Catalyst of Aeons epic is also an incredible first back buy. The Anguish on the other hand while better vs tanks it also offers more ability haste for more ults and theoretical DPS. Though without the omni vamp and bonus HP you lose a lot of good sustain, Yes, Karthus does not need sustain it still helps a lot. The mana with the Anguish also does help if you build tear. Even with all that going for the Anguish, the extra dmg and true dmg on the passive of the Folly in addition to the sustain still makes this more beneficial in most cases. This of course is all theoretical, practice tool only tells so much and I have not played with the items enough to know for certain what works.


There are three other mythic items that could be built on Karthus only two of them so far looks like it can work. The first being the EverFrost, this item while having no good passive it does have a decent active that similarly to Hextech GLP-800 could be used. This active has a root as well and that's cool and all what it lacks is any % or flat pen. Without it and no good way to get more the item lacks dmg to any kind of character. This could turn out to be good later and I would not be too surprised but I'm not expecting it. In regards to the Hextech Protobelt-01 it is nothing new, it was not good on karthus and still will most likely not be. The new night harvester item seems interesting, it has a similar MS passive like ludens and ability haste like the anguish but again no pen of any kind make it a hard sell. The passive adds a nice chunk of dmg to ability's similar to Ludens but applies individually to each champion making it better than ludens. No mana adds another problem but its not impossible to get over, the main problem is still the lack of pen and I believe the game with the new items is all about pen for mages. So in all I don't see this item getting used either but maybe it sees its time in the spotlight.
Other lanes - ADC - Top Back to Top

Top lane is the least played role for Karthus, that he can be played in, and for a few reasons. Karthus can have a very difficult time out sustaining, out damaging, or just surviving against many top lane champions, namely bruisers. Karthus has okay match ups into a decent amount of tanks but still fails to be able to beat the best ones such as Maokai or Poppy. Then we get to bruisers who can just kill and dive you outright most of the time due to not having Barrier or Exhaust. You are often forced to buy Rod of Ages just to survive. Top lane Karthus can work but has its flaws for sure, though it has some decent ranged top lane match ups like Teemo. Just never pick Karthus top blind is the moral of the story.


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 Ardent Censer 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 build the Dark Harvest Luden's Echo build to play aggro in lane. Very rarely will you be playing safe in bot lane unless they pick Lucian Leona or something even more aggro than your lane. But that does not mean that the scaling build does not work bot, a support also helps keep you safe to scale but of course it will take longer to get to the needed items like Archangel's Staff but it can work. Though being behind in levels with the other lane does make carrying from bot lane more difficult as you rely heavily on ability damage.
The late game plan Back to Top

This is a lane and build guide but here are some pointers on late game anyway.

While yes Karthus is a late game champion, but he is not as strong as 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. 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 player 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.

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 Back to Top
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