TV-Series
Description
Deusolbert Synthesis Seven is a high-ranking Integrity Knight in the Axiom Church's order for the Human Empire. Initially patrolling northern regions like the Norlangarth Seventh Remote Region, including Rulid Village, his duties changed drastically after Alice Zuberg violated the Taboo Index by touching soil in the Dark Territory. He was dispatched to apprehend her, arresting Alice with a restraining tool, transporting her via dragon to the Central Cathedral, and delivering her for imprisonment and transformation into an Integrity Knight. Administrator Quinella erased his memory of this event and his life before knighthood as part of her control, resulting in his promotion to guard the Central Cathedral.

His appearance features ashen-red hair and eyebrows like rusted iron, a high nose bridge, sharply defined lips, and eyes likened to steel arrowheads, typically presenting as a man in his forties. He first wore meticulously polished silver full-body armor with dragon motifs and a face-obscuring visor. After reassignment to the Cathedral guard, his armor became copper-red.

Deusolbert wields the Divine Object "Conflagrant Flame Bow," generating fiery arrows through its Armament Full Control Art. Years after Alice's arrest, he confronted Eugeo and Kirito in the Central Cathedral's equipment vault. After initial arrows failed to immobilize them, he escalated to his bow's flame abilities. Eugeo wounded his shoulder and froze his arm with the Blue Rose Sword's ice. Forced into defeat, Deusolbert questioned his mission's integrity upon learning from Kirito that Administrator manipulated his memories, erasing his role in Alice's capture. This caused a crisis of faith; he warned the duo of coming dangers while requesting they end his life to avoid dishonor, a request they declined.

Following Administrator's demise, he defended against the Dark Territory invasion at the Great Eastern Gate, leading the right flank of the First Unit alongside other Integrity Knights. His specific actions in this battle are not elaborated upon, but his role highlights his commitment to the Human Empire's survival. His ultimate fate remains unspecified in the anime adaptation, though alternate source material suggests a different outcome.