Damian operates as a key agent for a covert Jahana Group splinter faction dedicated to the deceased Miranda Jahana, opposing her daughter Reimi. His core mission is advancing the "Black Goddess" project, designed to resurrect Miranda by identifying a suitable host body and manipulating them within the Variable Geo tournament.

He targets Satomi Yajima as the ideal host, recognizing her potent latent spirit energy and exploiting her vulnerability stemming from her brother's illness. Damian secretly orchestrates a relapse in her brother's condition, then offers to fund the expensive medical treatment in exchange for Satomi's participation in the tournament and submission to experimental procedures.

Demonstrating significant martial skill, Damian ambushes Yuka Takeuchi, Jun Kubota, and Manami Kusunoki at Yuka's dojo. He easily defeats all three combat waitresses, leaving them near death after they discover their murdered students. Only the intervention of a mysterious old master prevents their demise.

His role involves direct confrontation. During a later clash with Yuka, Damian deliberately provokes her into unleashing her full power, understanding she underestimates her own capabilities. This tactic succeeds, forcing Yuka to execute her ultimate technique, "Soryu Gekki" (Shooting Star), a lethal ascending strike. The technique kills Damian instantly, achieving his apparent goal of witnessing her true strength at the cost of his life.

Damian exclusively appears within the narrative of the original Variable Geo OVA.