Grimms, a Busoma forged from the corruption of cursed weapons, pursues ambitions beyond mere annihilation. A master manipulator, he engineers clashes between Busoma and Chrysalises—humans bound to cursed arms—subtly tipping battles to fuel chaos. During Gai and Seiya Ichijo’s confrontation, he intervenes to ensure the demonic blade Zsoltgewinn escapes, extending turmoil.

His ultimate aim centers on corrupting potent Chrysalises like Gai and Seiya, twisting them into Busoma to serve his inscrutable designs. This is starkly demonstrated when he seizes the power of Takuma Miura, a fallen Shoshidai administrator briefly restored to humanity after Zsoltgewinn’s purification. Grimms frames this act as a quest to “understand humans,” yet his deeper intentions stay shrouded.

Operating in the narrative’s shadows, Grimms avoids allegiance to humans or fellow Busoma, embodying a spectral threat. His mere presence chills allies and foes—Kyouka Kagami recoils in primal terror at his arrival. Even as final conflicts erupt, he lingers on the periphery, observing pivotal battles and cementing his role as a perpetual danger transcending the story’s central struggles.

Though his origins remain undisclosed, Grimms’ methods hinge on cold calculation: exploiting vulnerabilities, testing resolve, and trading influence for strategic gain. His interactions lack personal ties, revolving solely around furthering his obscured agenda through manipulation and opportunistic power consolidation.