ONA
Description
Di-amon is a prominent antagonist from the Hell's Requiem arc, serving as one of the Three Sorcerer Generals. He is a powerful and immortal vampire, specifically a True Ancestor, which marks him as one of the most formidable immortals in existence. Originally a human sorcerer, Di-amon used his magical abilities to transform himself into a vampire, a deliberate act to escape what he perceived as his grotesque human form. Unlike his fellow Sorcerer Generals who were trained by their leader Arshes Nei, Di-amon already possessed immense power when he joined her ranks.

His personality is defined by extreme egotism and a deeply skewed perception of beauty. He considers his monstrous, blue-grey skinned vampire form, marked by bulging muscles and a white skull tattoo covering his face, to be incredibly handsome. In stark contrast, he despises his original, which is that of a slender, conventionally attractive pretty-boy, declaring that form to be ugly. This vanity extends to his physical presentation, as he wears gaudy makeup and his overall design is a direct homage to the real-life Danish heavy metal vocalist King Diamond.

Di-amon's primary motivation is the acquisition of greater power. He seeks to surpass his fellow Sorcerer Generals, Arshes Nei and Kall-Su, a goal he pursues by collecting and drinking the blood of virgins to enhance his own abilities. This ambition leads him to conspire against his own allies. He devises a plan to kill both Arshes Nei and Kall-Su in order to steal their power for himself. This treachery places him in direct opposition to the protagonists. Seeing an opportunity to eliminate the powerful wizard Dark Schneider, who is trapped in a weaker body, Di-amon kidnaps Lucien Renlen and Tia Noto Yoko. His violent actions against his hostages and the heroes inadvertently trigger Dark Schneider's release from his seal, leading to a direct confrontation.

In his battle with Dark Schneider, Di-amon initially proves resilient, resisting many of the wizard's spells. However, the tide turns when Dark Schneider catches one of Di-amon's signature attacks, the Assassin beam, and redirects it to destroy a wall, exposing Di-amon to sunlight. As a vampire, sunlight is a fatal weakness, causing him to disintegrate into dust. He survives this by transforming into a giant bat and attempting to flee, but Dark Schneider captures him and forces a curse upon him, the Blue Nail Curse of the Accused, which compels him to serve his former enemy and never act against him again. His key relationships include his subservient vampire Jodoh, whom he punishes harshly for failures like bringing a non-virgin to be his meal. He also has a pre-existing acquaintance with the warrior Kai Harn, whom he later bites to drink her blood for power.

Di-amon experiences notable development after being cursed into servitude. Following a two-year time skip, he reappears as a loyal subordinate to Dark Schneider. He infiltrates the Castle of Judas with the intention of killing Kall-Su, stating that he acts in dedication to the resurrection of his great master, Dark Schneider. Despite being confronted by Kall-Su's elite Sorcerer Shoguns, Di-amon's power, further amplified by the full moon, allows him to defeat them with ease. He even reveals the true, corrupted form of the castle, which had been hidden by illusions created by the god-like being Anthrasax. He then challenges Kall-Su for the throne of Judas, which he intends to hand over to Dark Schneider. Ultimately, he is defeated by Kall-Su, escaping not as a giant bat but as a flying severed head with bat wings, demonstrating his remarkable tenacity and unorthodox methods of survival.

Di-amon possesses a wide array of supernatural abilities stemming from his vampiric nature. He has enhanced strength, enough to send a person through a wall with a single punch, and a healing factor that can rapidly recover from profound cuts and burns. He has an acute sense of smell, capable of identifying a virgin by scent alone. His magical abilities are considerable; he can transform into an overgrown bat and has a natural resistance to damage from most weapons and spells, though lightning and ice magic can still harm him. His signature attack is called Assassin, a powerful beam of death fired from his eyes that can explode targets. He can also perform variations of this, such as the Mega-Spin Vampire Assassin. Other spells include Domain, a bolt of energy from his hands, and Energy Drain, where he bites an opponent to suck their blood and grow stronger. A notable ability is his resurrection: if destroyed by sunlight, he can return to his coffin as a bat, feed on spirits in the underworld, and be reborn two days later. His power is also significantly enhanced by the light of the full moon.