Defrott is an S-class vampire appearing as a young man, short in stature with blue slitted eyes that turn red in his vampiric state, and naturally soft, fluffy curly hair. He dresses professionally in white pants, a creme-colored coat featuring a navy blue interior and ruffle-ended cuffs, a white undercoat with a ruffled collar, and brown boots.

Intelligent, mysterious, and widely recognized as a stage actor and singer, Defrott speaks maturely and possesses a pronounced obsession with beauty. As one of the world's oldest vampires existing for centuries, he grew increasingly detached from humanity. His existence centered on performing at the Imperial Theater, where he found fleeting purpose only on stage.

His detachment shifted through his bond with fellow actress and vampire Misaki Nakajima, who reconnected him to his humanity. Misaki's death profoundly impacted Defrott, triggering uncharacteristically reckless grief. After her loss, he formed a friendship with human journalist Aoi Shirase, who bears a striking resemblance to Misaki. This resemblance fostered Defrott's tolerance for Aoi's presence at the theater and later motivated protective actions toward her.

Due to his S-class rank, Defrott possesses considerable vampiric abilities, surpassing powerful A-class vampires like Shutaro Kurusu. He demonstrates high-speed movement, combat prowess against formidable opponents such as Maeda, and resilience in harsh environments, though he typically avoids conflict unless compelled. During a critical confrontation, he strategically called upon Kurusu to rescue Aoi from sunlight using specialized protective equipment.

Defrott serves as an informal narrator for the epilogue, reflecting on the story's events and themes. His dialogue frequently incorporates lines from stage plays, especially during intense or reflective moments, reinforcing his actor identity and adding depth to interactions. His final acts emphasize themes of sacrifice and closure, consistent with tragic motifs from his theatrical background.