Lightbringer

Demon lord Orephoron Sanguineus has been stuck on earth for the last hundred years or so, after a human summoned him, bound him to the earth until he fulfilled one task, and then went and died of a heart attack without ever specifying that task. Orephoron now spends most of his time trading favors and souls, trying to hopefully find the jerk who stranded him or somebody else who can free him.