Diodora Astaroth

Diodora Astaroth was the supposed heir of the Astaroth Clan after his older brother Ajuka took the title of Beelzebub. He was one of the main antagonists in Volume 6 of the light novels.

Appearance
A gentle-looking, handsome young man with blonde hair (Dark green in the anime). He was usually dressed in the noble clothing. In the anime, Diodora has black hair.

Personality
While initially appearing to be a gentle, well-mannered young man, Diodora was in fact a narcissistic, sinister, vile, and wicked person who would do "whatever it takes" to achieve his desires. He has an utterly obsession with nuns and holy-maidens, 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 enjoys seeing them in an expression of pain, sadness, and despair as he finds it to be an ultimate form of entertainment.

He is shown to have a loathing expression towards Dragons and those connected to them, as he called Issei a "filthy dragon". But after suffering his defeat by Issei, he became immensely fearful towards him and dragons.

History
It is stated by Freed Sellzen that due to his nun fetish, he's been preying on famous nuns and Holy-maidens in various countries around the world one after the other. He would often seduce the maidens with his passionate words in order to make them fall in love with him. After the nuns and maidens were cast out by the church, which is devastating for them, he would later save them from the depths of their despair, and eventually rapes them in both body and heart. Later Diodora reincarnated them into becoming his servants as they slavishly pledged their loyalty to him as a result.

Sometime prior to the series, 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.

Birth of the Breast Dragon Emperor
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 group 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 battle against the Gremory group. 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.

Powers & Abilities
Demonic Powers: Diodora has shown some skills in using his demonic powers, able to hurl conjured blades at Issei during their fight.

Trivia

 * Diodora makes a brief cameo in chapter 21 of the manga at Rias and Riser's engagement party (he is the figure on the third panel on page 51 of the magazine version in the back).