|“||This must be a lie! There is no way I will be beaten! I won against Agares! I’m also planning to win against Bael! There’s no way I will lose to the untalented heir of the Great-King! Gremory who holds affection can’t even be my opponent! I’m Diodora from the House of Astaroth!||”|
–Diodora's breakdown upon being defeated by Issei, Volume 6, Life.4 I Love You
Diodora Astaroth was the former heir of the Astaroth Clan. He was the son of Lord and Lady Astaroth.
He was a gentle-looking, handsome young man with blond hair as depicted in the novel (dark green hair in the anime). Diodora also had a big deep scar on his chest from when he injured himself to have Asia heal it as part of his plan to make her a heretic. He usually wears expensive clothing. He also has golden eyes, but they are almost always closed or squinted.
While initially appearing to be a gentle, well-mannered, and charismatic young man, Diodora was in fact a narcissistic, sinister, vile, callous, and wicked person who would do "whatever it takes" to achieve his desires. He had an utter obsession with nuns and holy-maidens, which was exemplified by the fact that all of his servants were once nuns and maidens that he had acquired after "breaking" them. He enjoyed seeing them with expressions of pain, sadness, and despair which he found to be an ultimate form of entertainment. This showed Diodora to be an incredibly sadistic Devil.
He was shown to have a loathing towards Dragons and those connected to them: he once called Issei a "filthy dragon". After being defeated by Issei, he became immensely fearful of him and dragons as well.
He was also very imprudent, as was exemplified when he used the Ophis' power in a careless way despite Shalba Beelzebub forbidding him from doing so, as it allowed the Three Factions higher-ups such as Sirzechs and Azazel to catch wind of the Khaos Brigade's plot due to noticing his irregular increase in power. Despite this, he is very intelligent, deceptive, and manipulative, capable of manipulating others into doing his bidding. An example would be how he managed to convince the nuns and holy-maidens who would become his servants that he was in love with them, only to use them for his own twisted pleasure, showing that he is also incapable of love.
It was stated by Freed Sellzen that due to his nun fetish, he had preyed on famous nuns and Holy-maidens in various countries around the human world. He would 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 their churches, which left them devastated, he would appear before to supposedly save them from the depths of their despair, only to eventually be taken advantage of; rape and mentally break them in both body and heart. Diodora would then reincarnate them as his servants who slavishly pledged their loyalty to him.
Sometime prior to the series, when he set his sights on his next target, Diodora purposely injured himself and appeared before Asia, who healed him. This act of healing a Devil resulted in Asia's eventual excommunication from the Church. He was also present when Raynare stole Asia's Sacred Gear, intending to kill Raynare, save Asia, and then take her as his servant. This plan failed when Issei defeated Raynare and Rias revived Asia instead.
Sometime before the series began, Diodora made an alliance with the Khaos Brigade, receiving one of Ophis' serpent to acquire great power. He used this power boost to murder the next head of the Glasya-Labolas clan, something all thought was an accident.
Powers & Abilities
Demonic Power: Diodora showed some skill in using his demonic powers, as he was able to hurl conjured blades at Issei and create barriers during their fight. His power was greatly enhanced with Ophis' snake, surpassing Rias Gremory's demonic power and allowing him to completely overwhelm Seekvaira Agares, another High-Class Devil, with ease.
Magic: Diodora showed some skill in using magic.
- Defensive Magic: Diodora demonstrated the ability to create a defensive magic circle to shield himself against attacks. He also demonstrated the ability to create a large barrier to trap Issei in order to stop his attacks.
- Teleportation Magic: Diodora has demonstrated the ability to teleport himself and others.
- Hypnosis Magic: In the anime, he used a form of hypnotism on his peerage to suppress their shame and embarrassment to fight against Issei's Dress Break spell.
Ophis' Snake: After joining forces with the Khaos Brigade, he obtained a snake which he used to increase his power. He used it during his Rating Game against Seekvaira Agares and his fight with Issei Hyoudou.
- Diodora was one of the young Devil heirs and Kings chosen to compete in the Youth Devil Rating Game Tournament.
- Diodora made a brief cameo in chapter 21 of the manga at Rias and Riser's engagement party.
- In the English dub of the Highschool DxD BorN, Freed Sellzen called him "Diodora The Explorer". This may be due to his hobbies of exploring various places searching for holy maidens. It may also be a reference to the children's show "Dora the Explorer."