Abyss Demon

Abyss Demon is a demon summon from Mass for the Dead.

Personality
Abyss Demon possess intelligence to speak human language and strength to crush rocks. He combines obedience that faithfully carries out its life in the service of Demiurge and Momonga. Ferocious in that, if he considers those as an enemy, he will crush them without mercy. Abyss Demon may look like a thug, but he has a prudent mind and can sense an enemy's power.

Background
One of the subordinates summoned by Demiurge during the Great Tomb of Nazarick's crisis.

Mass for the Dead
During Nazarick's abrupt transition into the [New World, Demiurge summoned this demon to assist the main character.

Demiurge
Abyss Demon's summoner, and due to that he is loyal to him.

Momonga
Momonga being Demiurge's master is also loyal to him.