This is my first guide so any criticism is welcome =)

I have been playing Karthus for quite some time now and figured I would share some things I have learned. Now this is just how I play Karthus and you may disagree with me on some or all of it.

PROS

Amazing Farmer
Great harasser
Zone wide ult
Can do DPS after death

CONS

Very squishy
Can be shut down by silences or stuns
Generally main focus

x9 Greater Mark of Magic Penetration
x9 Greater Seal of Vitality
x9 Greater Glyph of Ability Power
x3 Greater Quintessence of Ability Power

Some guides recommend you using mana regen runes for your yellow.. I don't really agree with that due to the fact you won't have mana problems late game. Now the little extra health may not seem like much, but how many times have you been saved by 20hp?

Upon dying, Karthus enters a spirit form allowing him to continue casting spells while dead for 7 seconds.

This passive is very unique. It allows you to continue casting after death for 7 seconds. It gives you a great opportunity to use more more Lay Waste or Wall of Pain to assist your team further. Not to mention Requiem to assist in kills zone wide before you go down.


"Q" Ability
Creates a delayed blast at Karthus' cursor position. After 0.5 seconds, deals 40 / 60 / 80 / 100 / 120 (+30% of ability power) magic damage to each nearby enemy, this deals double damage if it hits only a single unit.

Cooldown 1 seconds | Cost 20 / 28 / 36 / 44 / 52 mana | Range 875

This is the bread and butter of Karthus! This allows you to farm easily early on and harass just about anyone. I can not explain how amazing this ability so I will sum it up in one word.. "WIN"
On a side note this ability does TWICE the damage if used on only ONE enemy. Meaning you can DESTROY people early on if they do not stick close to a creep.


"W" Ability
Creates a 800 / 900 / 1000 / 1100 / 1200 distance wide wall through target point. Reduces enemy armor and magic resistance by 15 / 20 / 25 / 30 / 35 and reduces movement speed by up to 40 / 50 / 60 / 70 / 80%; debuff lasts 5 seconds. The wall lasts 7 seconds.

Cooldown 22 seconds | Cost 100 mana | Range 1000


This ability will save you and allies numerous times in a game. Not to mention get your enemies killed many more times. Wall of Pain is so easy to place due to its large size. You can very easily kill someone with just one slow in conjunction with Lay Waste


"E" Ability
Toggle Off: When Karthus kills a unit, he restores 20 / 27 / 34 / 41 / 48 mana.

Toggle On: Drains 30 / 42 / 54 / 66 / 78 Mana to deal 30 / 50 / 70 / 90 / 110 (+25% of ability power) damage to nearby enemies each second.


This ability has two uses. The passive which allows you to regain mana when you get the killing blow on a unit or hero as well as a amazing AOE. Be warned though early game it will deplete your mana pool very quickly but still has its uses. Late game it is a KILLING MACHINE. I can not stress this enough... DO NOT forget to turn it on when you die and people are around!


"R" Ability
After channeling for 3 seconds, Karthus deals 250 / 400 / 550 (+60% of ability power) magic damage to all enemy champions (regardless of distance).

Cooldown 180 / 150 / 120 seconds | Cost 200 / 300 / 400 mana | Range 10000

Cooldown 0.5 seconds | Range 550


This is the spell Karthus is really known for. He IS more than just a "R" but this ability really pisses people off. This ability is great for so many situations... you can kill the pesky hero who got away from you or a teammate with low HP. You can use it after you die to kill someone OR assist in the DPS of their team while you are dead. I do not recommend using it just to steal kills because you WILL piss your team off.

1 of 2 of my recommended summoner spells. Since Karthus is so squishy it is invaluable to have a way to escape a fight. Wall of Pain and Flash used together is almost impossible to catch up too.


2 of 2 of my recommended summoner spells. This just like Flash is a great way to escape ganks with ease. Wall of Pain goes great with this summoner.


Teleport is also a great spell to use. Very useful for getting back to your lane/porting in to a fight or saving a tower. I just feel the survivability of Flash or Ghost outweighs the benefits of this.


Ignite COULD be useful in certain situations but not more than Ghost or Flash. You already have ways to kill people who run. This upside to this is the healing debuff.


Awful summoner for Karthus. If you pick this please punch yourself in the face.


Sure this is great for the first 3 levels.. then what?

I go the standard 9/0/21 for maximum utility.

Gives Magic Pen
Extra Ability Power
Extra XP Bonus
Mana Regen
Flash/Ghost CD
Lower Ability Cooldowns..

Now I have seen people go deep in the defense which if you are just starting out may not be a bad idea for more health and defense to survive.