Relatives: Ajuka Beelzebub (older brother)
Ranking: High-Class Devil
Race: Pure blooded Devil
Role: King
Status: Deceased

A gentle-looking, handsome young man with blonde hair. He was usually dressed in the normal clothing of a Devil noble.

History:
In the past, Diodora purposely injured himself to force the kind Asia to heal him, a Devil, which resulted in Asia's accusation of her being a heretic which led to her excommunication from the Church. He was also at the abandoned church at Issei's town when Raynare stole Asia's Sacred Gear, initially intending to be the one to kill Raynare and save Asia and then take her as his servant. His plan, however, did not work due to Issei defeating Raynare.

He appeared in volume 5 as one of the six young Devils for the Young Devil Gathering. At the end of the same volume, he reappeared in front of the Gremory Team and proposed to Asia after he revealed that he was the Devil that Asia healed years ago.

In volume 6, he was scheduled to have a Rating Game against the Gremory Team but this did not happen after he revealed that he was an ally of the Khaos Brigade. He also reveals he had Asia heal him simply to add her to his collection of nuns. Diodora then kidnaps Asia and has his peerage deal with the Gremory Team. He was defeated by Issei in a one-on-one fight with Issei overpowering him out of rage at what he did to Asia. After his defeat, Shalba Beelzebub appeared. Diodora pleaded with him to help, only for Shalba to stab him with a weapon of light, and his body dissolved away.

Diodora had at least moderate demonic powers, but was suggested to be the weakest of those related to the current Satans. However, he did show some skills wielding it, even hurling conjured blades at Issei during their fight.


Personality:
While initially appearing to be a gentle young man, Diodora was in fact an evil and twisted person. He had a nun fetish, which was justified by the fact that all of his servants were nuns and maidens that he had acquired from all over the world after "breaking" them. He also seemed to have a strong disliking for Dragons and those connected to them, as he called Issei a "filthy Dragon" (volume 6).
(Source: High School DxD Wikia)