Diehauser Belial

Diehauser Belial is the current head of the Belial Family (ranking at King) and the number one-ranking Rating Game champion.

History
Not much is known about Diehauser, other than the fact he has dominated the Rating Game for a very long time, being undefeated since appearing, and is popularly known as "The Emperor" (皇帝 Kōtei) to everyone.

Plot
He was one of the spectators at Rias and Sairaorg's Rating Game, complimenting Issei and Sairaorg for their magnificent fight.

In Volume 12, Diehauser and his peerage went to fight against the Jabberwocky created by Leonardo's Annihilation Maker but was only capable of stalling it. He later leads an alliance army from various faction to battle the Bandersnatch being the first group to defeat the monsters.

Powers & Abilities
His powers are said to be on par with the current Satans.

Trivia

 * In demonology, Belial is one of the Four Crown Princes of Hell and a demon in the Bible. He is said to be a mighty and a powerful king, ruling over fifty legions of demons made after Lucifer.