Lucifer

Lucifer is Satan himself, the King of Hell and the ruler of evil. His first appearance in the Multiverse is in the Hell's Broken Angel storyarc, where Deathwalker, a soul damned in a low corner of Hell, enters a pact with him. The terms of their pact state that as long as Deathwalker can find, kill, and deliver pure, innocent souls to Hell, then he will be spared from eternal torment for a time.