Demiurge originates from the *Overlord* series, a demonic entity created by Ulbert Alain Odle. He commands the 7th Floor of the Great Tomb of Nazarick as its Guardian and serves as Commander of the NPC defenses, acting as second-in-command among the Guardians. Within his home series, he adopts the alias "Jaldabaoth," presenting himself as a Demon Emperor to orchestrate conflicts in human nations such as the Re-Estize Kingdom and the Roble Holy Kingdom. His manipulations include inciting wars between humans and demi-humans, conducting inhumane experiments on captives termed "Abelion Sheep," and utilizing their remains for crafting materials. Demiurge exhibits extreme loyalty to Ainz Ooal Gown, frequently misinterpreting casual remarks as complex schemes, while maintaining genuine camaraderie with Nazarick's inhabitants. His personality combines high intelligence and strategic cunning with innate cruelty towards outsiders, taking pleasure in inducing despair through psychological torment and physical suffering.

In *Isekai Quartet* and its film *Gekijо̄ban Isekai Quartet ~Another World~*, Demiurge's portrayal adapts to the comedic crossover setting. While retaining his core loyalty to Ainz and analytical nature, his darker traits are subdued. He adheres strictly to school regulations and collaborates with classmates to enforce rules, exhibiting no overtly malicious behavior. He respects Tanya von Degurechaff for her adherence to order, considering her an exception among humans. His interactions with others are pragmatic, such as using a Command Spell on Kazuma Satou to prevent rule-breaking like peeping.

During the film's events, Demiurge is transported via a wormhole to a facility housing golems. He joins a group including Shalltear Bloodfallen and Aura Bella Fiora, encounters the golem Pantagruel, and travels to a village. Later, he participates in a coordinated effort to combat a rampaging golem, aligning with the collective goal of returning home. His abilities include tactical planning, magic use, and the Command Spell, though his combat role remains secondary to his organizational skills.

His background as a meticulous planner and craftsman includes hobbies like carpentry using materials from his experiments. This aspect is omitted in *Isekai Quartet* in favor of focusing on his rule-enforcement duties and cooperative dynamics within the ensemble. His inherent demonic nature persists, but the narrative emphasizes integration over conflict, showcasing interactions devoid of his typical sadism. This results in a version operating within the comedic framework while maintaining his strategic intellect and loyalty to Ainz.