Inimicus acts as Duke Dortesheim's advisor, secretly serving as an accomplice to Lady Shade. She orchestrates the Duke's rebellion and the ensuing civil war from the shadows, with Inimicus manipulating events to advance these destabilizing ambitions.

He wields the Darkness Curse, a power derived from Shade's elemental magic. This ability allows him to cast potent spells, including one that historically triggered the Bloody Rhapsody roughly two centuries before the main story. That spell transformed living soldiers into berserk, zombie-like entities. Mirroring this tactic in the current conflict, Inimicus employs mind-control magic to manipulate soldiers into frenzied combatants, turning them into instruments of war. His actions extend to supplying a Magic Stone to an individual named Nilgan, furthering the rebellion's goals.

Physically, Inimicus is an adult male. He has black hair reaching chest length, typically secured in a ponytail. His features include a mustache and a goatee, forming a distinctive visual design, with brown eyes noted in character records. The documented materials provide no significant background details, character development arcs, or expanded narrative roles beyond his involvement in the civil war plotline.