Karthus

 is a Mage Champion in League of Legends.

Story
The vast quantities of magical energy that have been released during Valoran's numerous Rune Wars have scarred much of Valoran. Many remote locales continue to be twisted by residual magic, making them places where few dare to go. The Howling Marsh is one of these places, and the self-appointed overlord of this land is the lich known as Karthus. Some speculate that Karthus was a mage in life who was foolish enough to enter the fetid waters seeking his fortune, and that he was forever transformed by whatever dark magic permeates the swamp. On the darkest of nights, Karthus is said to sing the tales of those who have succumbed to the swamp, past and present.

Karthus has come to the League of Legends seeking personal magical power and influence. While not entirely malevolent as an undead lich, he cares little for the consequences of death upon the living. Karthus can make the ground beneath his foes erupt, causing massive damage to those caught in the blast. He can create a wall of tangible pain, crippling foes who are foolish enough to pass through it. Being a lich, he feeds off the misery of others in two different ways – either defiling the environment around him or feasting on the magical essence of those he fells in combat. Karthus also may sing the song of death itself; those who hear his baleful dirge are wounded to their very soul, and it is nearly impossible to escape hearing this woeful aria.

Strategy

 * 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.