The firstborn of Demon King Hadasht, he is the most powerful of the Ten Great Nobles and the candidate most likely to prevail in the Succession War. Although he inherited the title of 天魔 previously held by his father, he was never named as his successor which sparked the current Succession War. Ambitious and extremely arrogant, he offers Primtine an opportunity to surrender when they finally meet at the end of Farinasea's route. He shares the typical prejudice of demonkind against Fabio's kind and dismisses him as unworthy of his time and of Farinasea's affections. He was privy to the secret behind Primtine's castle and was suspected of behind his father's murder. He nominated Grail as a Great Noble and sponsored his research into creating an invincible undead army to keep the promise made with his dying mother; that Primtine be kept safe from harm at whatever the cost. He dismissed his father's method of ruling as weak and ineffectual, believing the only way to properly administer the demon realm is through indomitable power. Although he knew the truth behind his father's sudden death, he chose not to share it with his sister to keep her safe from Volja. His artefact 天を統べる物 allows him to freely manipulate the flow of mana in a given area. Since mana sustains the vitality of all inhabitants, Ardbelt is very difficult to kill provided he can sustain himself with an unlimited source of mana from the atmosphere. In Farinasea's ending he serves as Fabio's bodyguard and grudgingly accepts their relationship. He cannot oppose his sister's will as she begins to increasingly resemble their father with each passing day and is terrifying when crossed.