Mephisto

Mephistopheles, also known as Satan, Lucifer, "The Devil" and Mephisto, is a fallen angel in the Marvel Universe.

Mephisto is the ruler of Hell, the biblical realm which houses and punishes impure souls. Mephisto is not a physical threat, but rather a presence on earth who has the ability to consume the astral energy of souls to fuel his sinister, tempting influence.

He is yet to appear in Marvel Legends as a character.

History
Mephisto is believed by some to be the literal Devil of various faiths, while others believe he is an ancient dimensional entity which inspired or invented the concept of a Devil in all religions.

Mephisto claims he is formerly known as Lucifer, an angel who allegedly turned on God and His angels and was banished to Hell. He credits himself for influening and harvesting evil throughout mankind's history.