Karthus Build Guide by Cruxispal

Not Updated For Current Season

This guide has not yet been updated for the current season. Please keep this in mind while reading. You can see the most recently updated guides on the browse guides page.

League of Legends Build Guide Author Cruxispal

DIE DIE DIE WHY WON'T YOU... i just died

Cruxispal Last updated on November 12, 2011
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Team 1

Ability Sequence

Ability Key Q
Ability Key W
Ability Key E
Ability Key R

Not Updated For Current Season

The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.


Brute Force
Improved Rally

Offense: 9

Strength of Spirit
Veteran's Scars

Defense: 0

Expanded Mind
Blink of an Eye
Mystical Vision
Presence of the Master

Utility: 21

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Hello Summoners and Welcome to my Karthus Build. Many players seem to look down upon poor Karthus, and through his endless sorrow, all the skin fell off his face. Okay... maybe his skin fell off a bit before that. Anywayz he needed hugs, so what better way to give him his much needed hugs by presenting a guide through Mobafire?

This is also, my first build on Moba, so be nice guys =P

-Changelog and Updates-
Nov 9, 2011- Accidentely hit the publish button. You get to see my progress now, yay....
Nov 12, 2011- Guide completed. Working on adding a few more things, but overall it's done.

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Pros and Cons

So many of you probably came in with the mentality that Karthus is an annoying KSing troll character... AND HE IS! That what makes him so good. When your enemies are pissed off, they will usually play worse than they regularly do. See? Pshycological Warfare. Anywayz on with the real pros and cons.

-His passive enables him to stay in battle and deal damage, and maybe kill off whoever killed you.
-Really good ap damage, consistent damage too, not one short burst, and then a long wait for cooldowns.
-Can slow down half the enemy team with his Wall of Pain
-His Lay Waste is great farming and harrassing spell.
-Global Ultimate for killing, annoying, pissing people off.

-Very fragile and squishy
-Pretty slow
-A tad bit mana hungry

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I realized a lot of people said I didn't have rune explanations up. I realized I forgot to save my runes, but hey we're all human aren't we? Well... most of us anyhow. Here i'll present the standard runes, and then ones I feel are fun or even viable.


This actually is probably the only mark viable for Karthus. Magic penetration on marks, just scale so well with any AP caster I don't see why you wouldn't take it. You can't even troll AD Karthus, like some other mages =/

Greater Seal of Vitality or
One of Karthus's only problems is his squishness. Some may argue that he's gonna die easily anyways, so don't even bother giving him health. This may be partially true late game, but early game you still need your health to stay in lane. So if you want a beefier late game go for [Great Seal of Vitality] for a stable early game, [Greater Seal of Fortitude]

If you just want to go head on AP, then these would be the seals for you. A bit of warning, You will die many times like this, but hopefully you'll get your share of kills and assists as well.


I recommend these rather than the seals, as these just gives you so much more AP then the seals. Seals have stronger defence, Glyphs stronger magic. I advise you guys to stick to each rune's own benefits, unless you want to go pure AP or something along those lines.

Greater Glyph of Replenishment
These will help you mainly early game, where you have the most mana problems. It'll also help you a bit late game, but by that time you should be constantly grabbing blue. If you just seem to always go out of mana, then these might work for you. Otherwise I think Greater Glyph of Ability Power is much more viable.

Now these are the fun ones, essepically if you got money to blow. Standard runes for Karthus will be:

Nothing more to say, then like the other AP runes. Just gives Karthus more power to deal out.

You read right. Revival. What these bad boys will allow you to do, is to charge into the middle of a teamfight, deal tons of damage. Die, and still deal tons of damage, and then comeback again. Teleport. And repeat until their dead.

Karthus has a really low speed. Most of his chasing and fleeing relies heavily on his Wall of Pain. These will allow you to flee away faster, and hopefully survive, or chase down that enemy so you can get the kill.

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I go a standard 9-0-21 Mastery setup.


You get the additional Ability power, the Cooldown Reduction, and the Magic Penetration which is what your really after. Some might want to get the revive in the defense mastery, but i feel getting 21 into utility is more important.

Now another idea that I tried, and works pretty well is a 8-1-21 set up. This concentrates on zombie karthus, a strategy i'll explain later on.

What this concentrates on is your getting back alive as quick as possible. Taking one point in Preservation for the 30seconds revive cooldown. Good Hands to reduce death time. and Presence of the Master for even further cooldown.

This maximize's zombie karthus getting back into the fight strategy, but at the cost of 15% magic pen, which is a signifigant amount. But 30 seconds cooldown on revive is also pretty big deal as well. Once again, its up to how you play Karthus.

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Skill Order:

Now lets take an indepth analysis of Karthus's skills.

This is Karthus's amazing passive. It allows you to stay 7 seconds after wards to try to get some revenge on you assailants. But remember, your ultimate Requiem takes 3 seconds. Lay Waste has a one second cooldown, not to mention a 0.5 second delay. So use your skills wisely. Remember to cast Wall of Pain in teamfight to slow down the enemy team, as well as activate Defile as it gives AoE damage.

This is Karthus's bread and butter. Its your harrasment, farming, trolling, whatever skill. It has a 0.5 second delay before blowing up wherever you pint your mouse cursor. It has a small AoE damage, and does twice the damage against enemies by themselves. And it costs only a tad bit of mana. Though, its easy to get carried away with this skill. It might be tempting to use this over and over to farm, but still try to last with this skill to save mana. I'll go on to a few strategies.

This is where you try to predict where your enemy will move to, so you can cast it in front or behind them a bit to have them walk into the blast. Usually you can predict where they walk by looking at a few specifics.

-When the go for a minion kill
When they step forward to farm, you can lay the blast while their moving to get the minion kill to either
A)make them walk away from the kill thus losing farm
B)Get damaged, harassed little by little, and finally killed.

When an enemy is chasing you, you can place it a few steps ahead of him to make sure he steps on the implosion. That combined with a nicely placed Wall of Pain can turn the tables giving you the kill, or at least buy time for allies to come and get it.

Hiding the Blast
A lot of times, you can cast it right on the minion, so the minion actually covers up most of the animation. Use this on minions close to the enemy champion, so that the aoe, deals a bit of damage to him. This constant harrasment, can quickly win you the lane.

Small Vision
This gives you a small area of vision where you cast it. So before you enter any bushes, be sure to cast it one to three times, because when I say small amount of vision, I mean a miniscule amount. Yet vision is vision is it not?

This is a really nice utility spell. Its a giant wall size of a lane, that slow all the pass through it. It can be really useful to cut of enemy team members, and it makes it easier for you to land your Lay Waste. You usually use this when your jungler comes to gank, or when your in a teamfight. This is also your only escaping tool, so use it wisely!

This is one of your big damage dealers. It has a nice passive that gives back some mana when you last hit something, this will keep you in lane for quite a while.

Its a really powerful AoE spell that keeps going. The good things about this is that there is no cooldown, its just a toggle on/off spell! So you'll always have it during teamfights. And as long as you have mana, this spell will be kept on to deal continious damage. The only problem with this, is it drains a hell load of mana, making this a not-so viable spell early to early-mid game. Also this plus Zhonya's Hourglass will deal tremendous damage.

Your godly, annoying as hell ultimate. This is a global spell, that does a good deal of damage. The one problem is that most new Karthus's freak out when they die, and immediatly cast it. Don't, this is a very vaulable skill, but only when used at the right time.

As soon as you hit lvl 6, tell your teammates to inform you when they almost kill someone, so you can start racking up some kills. And remember, your ultimate can be interrupted by stuns and knockups, so be careful. Also remember, it takes 3 seconds to cast, so, you don't have all day if you died and your in your passive mode.

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At the start you have quite a bit of choices. When you start the game you can roll out with

Starting Build

This will give you some mana regen, and some Ap to harass with. The problems with Doran's is that you can't buy health potions so your early game will be quite fragile. Also Doran's doesn't build into anything. Of course, at the end of the day its a reliable item.

A Sapphire crystal gives you a larger mana pool to work with, plus you'll have additional gold to buy a health potion in case they harass you a bit. Also this builds into a number of viable items later on. Get this if you want the largest mana instead of mana regen, or if you plan on building a Rod of Ages

This gives you mana regen instead, allowing you to stay in lane a bit longer, but at inconsistent farming levels. This does though give you two health potions, or a health + mana potion to work with. I usually get his or saphire and build into Archangel later on.

Early Game

Now that you farmed a bit, hopefully got first blood, you should be building your first core item. At this point you can choose whether to get boots first, or core item first.

Archangel Staff
I usually build Archangel's as it helps you continously abuse your spells. Also the extra Ap helps a bit too. You usually want to build this early so over time, your spells will stack up, so you can get more mana, and thus more ap.

This is the other choice. For Rod of Ages, you also want to get it early for its effects to build up into mid-late game. This gives you a bit more health to work on, and still a decent pool of mana. Not to shabby ap either. At the end of the day, its your preference.

Mid Game

Mid Game is where you get your heavy hitting Core items. Before these I suggest you get your upgraded boots. Sorc shoes are the obvious choice. There is honestly no other viable boots for Karthus.

Every Ap Caster in the history of League of Legend needs this item. This gives you a godly 140 Ap to work with, and an additional 30% ap. 30%! That takes all your ap together, and just adds another stack.

This is one of Karthus's most important item as it synchronizes with your [Defile] so well. First it gives you a nice bit of armor and ap. The armor to take a hit or two from those nasty AD Carries, and who wouldn't want more AP? But what really makes this item shine is it's active. It places you in a small time warp preventing anyone from damaging you, but also prevents you from casting spells or moving. The thing is, if you enter that time warp with your Defile on, it will continue to be toggled on. That's free damage your unleashing there, and they can't do anything about it!

You usually want to go behind your initiator or tank. The moment they make first contact, set up your Wall of Pain and walk into the middle of them. Toggle on your Defile and enter into your happy place.

Late Game

Here is where we wrap it off with some nice finishing items.

Abyssal Specter
This is a really amazing item. This along with Zhonya's Hourglass will help you unleash hell on your enemies. Not only does this give you decent AP, and magic resist, but it has an AURA that REDUCES enemy magic resist. That means, all of your enemies magic resist will drop, letting ALL of your team's ap casters deal more damage. It's basically a team magic penetration.

While in your Hourglass, dealing damage with hourglass, your also pro-longing the time your aura is there by not dying. Thus, big damage.

First of all, like all Karthus items, it gives you a good amount of AP. But what I like about this item, is it's other two componets. Karthus has always been extremely squishy. This added health, is a huge bonus to help Karthus survive longer in team fights. It also gives a pretty nice slow for chasing or escaping enemies.

Another option besides Rylai's is:

This gives you pretty good AP, and if you find the enemy stacking more magic resist than usual, this will help you crack through it.

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Other Optional Items.

I may not like these items, but that doesn't stop them from being viable.

Well I guess if your completly steamrolling the opposition, then this might be viable. But honestly lets admit it, Karthus dies quite a few time. He won't have that many chances to obtain those heavenly stacks before being kicked back down to hell again.

If your team is full of AP Casters, then this aurua will be a huge assist to your team. Though honestly, try to get a support to get this, or at least someone more beefy than Karthus.

First up and front, it gives you a good boost in armor, and a nice boost in magic resist. But what really is amazing is it's passive. It allows you to come back from the grave to exact more revenge. Imagine Karthus in the middle of your team dealing massive damage with his Defile. You kill him, but he rises up again! MOAR DAMAGE! You slice him back down again! And then he enters his passive to continue to annoy you to hell.

Maybe now, he's finally gone. WRONG! With revive, or his runes, he'll come back very quickly, and with a teleport, he'll be back with his team to deal more damage! The only reason I don't put this in the main build is that, AP really does stack better with him. But if your playing around in normal with your friends, then why not?

Now, some of you probably think Karthus is overly squishy. So I'm putting up some surivability items for you to swap in. I'd choose either Ryali or Abysall to swap out.

This has long been the ultimate survivability item for squisiess. So why not for Karthus. Not only does it give a decent boost in health, mana (and thus AP thanks to archangel), but also blocks one spell every 45 seconds!

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Summoner Spells

So there's a huge amount of summoner skills viable to Karthus. Some that usually aren't viable to other champions.

What I Get

This is a great spell for Karthus in general, though most often it is linked to Zombie Karthus. It lets you come back from the dead instantly, with rather high movement speed, or teleport, you can rush back into the fight. But you have to time this well. It has a rather long cooldown, so don't use it right when you die. There's a general checklist:
-Is an ally helping to control my lane?
-Is there a teamfight?
-Is there an immediate threat.
-Is there a chance I can come back, cast my ultimate, and pwn face?

These are the main things you want to check for before clicking on revive.

This synchronizes really well with revive, allowing him to die, and come back to the enemy in very little time. Also this helps solve a big chunk of Karthus's slow movement speed. Not to mention, 90% of the time, you will be mid, and if you go back, or die. You need to get back there quickly or thats 150 global gold for the enemy.

Other Viable Spells

I grouped these two together because they are their to solve one of Karthus's major weaknesses. His mobility. Its really down to preference whether you want to run around faster, or blink somewhere else. Generally speaking, Ghost is more consistent, it'll allow you to escape most enemies with the increase in speed. But CC will cut it down.

Flash on the other hand, can help you escape. But they'll still catch up if they have more movement speed. But if you're being slowed, or knocked around, a quick flash can blink you to safety. Not to mention you can flash over walls.

Karthus is generally mana hungry. A good player can manage his mana pool, but not everyone has the time to practice and get good, or maybe you just started. In this case, this can help beginners or just lazy people in general (like me).

Though still more suitable for the support, this is more viable for Karthus than other mages simply because of his ultimate. If you remember to keep using it to check on the enemy jungler, you might find a time that they're low health, and BOOM, their dead and raging and such.

I tend to dislike ignite on any champion simply because it becomes more and more useless as the game proceeds. Useful for those early game ganks, or first bloods, but in late game its just a small nuisance. Not to mention Karthus's killing ability doesn't really stack up till mid-game.

Yep, that's right. Smite. Jungle Karthus works quite well. I will explain Jungle Karthus later on.

I like this skill, though it doesn't belong on Karthus or any other mage for that matter. It's certainly useful for those first bloods, and its pretty useful in late game teamfights as well, you need to be busy spamming your [Lay Waste]. So all in all, possible, doesn't really fit Karthus.

Though you are gonna be targeted with CC, the second you cast this, your gonna be dead anyways. Karthus is just so fragile, and so slow to be putting this into any more use. [Ghost] and [Flash] are much better survival spells.


Honestly, if your team even gets this spell. It belongs on your tank or support.

No, just no. Once again, if your team does get it, tank or support.

Didn't it get removed? =D

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Lanining, Teamfights, Pwning

Here we discuss several of the strategies, we use on Karthus.

Early Game

During your early phases you want to be passive-aggresive. This means, constantly wearing down the enemy with small half-harrasments. There's another term I use. Half-Harrasements. You want to me able to get minion kills, and hit them at the same time. Maybe your waiting to last hit a minion, and in that time you hit the enemy just a bit. For the most part you want to be constantly moving, and getting as many minion kills as you can.


This is where you tend to start hurting them more. Be sure to notify your teammates that you have your ultimate, so you can blast people on other lanes to hell. If the enemy overextends then pop you Wall of Pain, followed by Defile and a few hits of Lay Waste to hurt them a bit. For the most part you don't want to wander unless your tower, or their tower in mid got shut down. Be sure to get blue, as it will help you a lot.

Late Game

This is usually when the teamfights happen. If your not doing anything, then clear our the jungle. Ward dragon and/or baron if nobody else is.


For teamfights you went to first cast your Wall of Pain to cut out some of the enemy champions so your team can burst one or two down. Next you toggle on your Defile ,and rush into the middle of them. Once their, activate your Zhonya's Hourglass to do a huge amount of damage. Once out continously pound them with your Lay Waste, and cast your Wall of Pain when it comes back up again.

How to initiate?
You want to follow your tank. Unlike other AP casters who stay in the back, for you to deal damage, you have to get into the middle of them. But if your the first one in, they'll slaughter you within seconds. So usually you want your tank, and another teammate to initiate first before going in. Like I said, when you go in, launch you Wall of Pain.

I'm Dead, Now What?
Luckily, you as a Karthus can still deal damage when your dead. Now you got to quickly analyze the situation.
-How many enemy champions are low health?
-Is my team winning, losing, or fairly even with the enemy?
-Do I have revive up?

If they have say three champions near death, immediatly cast your ultimate. If your team is kinda on the edge, your ultimate may turn it into their favor. But be sure to still deal as much damage as you can. If you have revive up, i advise you to not cast your ultimate, instead using it after you comeback and analyzed the situation again.

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The Dead are Coming Out of the Jungle!

Some may argue that this deserves a different build, but why not have all the Karthus info in one spot. Now those of you who have never seen Karthus jungle are probably laughing at me right now. But I assure you, its quite viable.

Right, I don't want an entire section within a section, so I'll just do a quick rundown over runes, masteries and such.


You want Magic Pen marks as usual, but take armor seals for more durability while in the jungle. Glyphs you can choose cooldown, or mana/mana regen. Cooldown will help later on in the game, but the mana will help your early game jungle. For Quints, I take AP, to make up for your lack of AP glyphs. You can take Health Quints if you feel like those will help in the jungle.


I take a 1/14/15 build. You take Plentiful Bounty for more smites, and more gold. I take 14 points in defense so I can get Defensive Mastery . I then take 15 in the utility for Utility Mastery . The last point I put into either Blink of an Eye or Haste depending on which skill I get.

Summoner Skills

: Pretty self explanatory. Jungler needs this skill.

or . Depends on your preference. This is used to help with your ganks, and speed problems. Ghost covers more distance, flash gets you out of tricky situations. I like flash, because a sudden blink combined with Wall of Pain can startle the enemy more than a kind of fast Karthus running out of a bush. Both works though.

Jungling Route

Red: Place wards here, dragon early on, baron later.
Green: Where you gank from.
Yellow: Place wards here if you are going to anti-jungle.

You start off at blue, since Karthus is extremely reliant on it. Without blue, his mana drops like a stone in water. That is why you want to get some mana or mana regen items right after you go back, or possibly just steal their blue. Anyways, have someone leash it, and you should be alright. Remember to catch the golem's aggro with an auto attack otherwise it'll just trot back to where it was with full health.

Next move onto wolves, wraiths, golems, and if you think you can, go for your first gank. I usually don't get red, because it's useless on karth, but if you want that extra exp, go for it.


I get Lay Waste at level one. You have someone leash blue, and just repeatedly blast blue with it. Finish blue off with smite. You want to use a health pot right after you get hit.

At level two I get Defile. Move onto wolves, and to wraiths. Blast the smaller wraiths so they come to you and auto attack. Then toggle on Defile to kill the small wraiths while you use Lay Waste on the big wraiths, since he's all alone now, it should do a lot more damage than otherwise. Move onto golems, kill and smite them.

At level three get either Wall of Pain if your going to gank right away, or another point in Defile if your going to continue ganking. Get Wall of Pain no sooner than lvl 4. When ganking, be sure to place your wall correctly to block the enemy's escape route. When your in the bushes, turn yourself so you can place the wall across the lane (Top to Bottom).

Be careful at the start. When people see a jungle Karthus, they might get the sudden urge to gank you. So make sure to get protection from the rest of your team. Besides that, Karthus is a extremely good jungler. He clears camps at high speeds, but at the cost of huge mana depletion. In fact if you want, you can get a few Mana Potion

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Karthus is an extremely powerful AP caster, and can utilize a variety of different, unique, tactics to turn the tide of battle. I hoped you enjoyed my guide, and to comment below. If you think I should add something, then notify me, and I'll test your theories (don't worry, I'll give you the credit). Also since this if my first guide ever, I would love any feedback you can give. Once again, Thanks and remember...


Coming Soon:
Having trouble facing certain champions. This man right here, will try to collect data, and help you beat those pesky little champs. Will also try out side lanes, just in case you get kicked to top or bottom during a game by an annoying Brand.