Phantom Karthus
Statue of Karthus
Grim Reaper Karthus
Pentakill Karthus
Fnatic Karthus
Karthus Lightsbane
Infernal Karthus
Pentakill III: Lost Chapter Karthus
The harbinger of oblivion, Karthus is an undying spirit whose haunting songs are a prelude to the horror of his nightmarish appearance. The living fear the eternity of undeath, but Karthus sees only beauty and purity in its embrace, a perfect union of life and death. When Karthus emerges from the Shadow Isles, it is to bring the joy of death to mortals, an apostle of the unliving.
Ally Tips

Ask your allies to help point out when you should use Requiem to get kills in different lanes.

Lay Waste is very strong at farming minions and harassing enemy champions.

Enemy Tips

Karthus can cast spells for a short duration after he is killed. Move away from his corpse to be safe.

Make sure you always have enough health to survive Requiem, even if you have to go back to the base more frequently to heal.