Kain is an angel with a heart of ice and wings of steel. His appearance exudes aristocracy, with perfect, marble-like features, a athletic build, and ash-blond hair that contrasts with his icy blue eyes. However, in moments of tension, his eyes can flash with a crimson glow, revealing his hidden power. His hands are always cold, with slender, almost fragile fingers that feel like ice on the skin.

Cain's character is a bundle of contradictions. He is cold, cynical, and irritable, and he does not appreciate sentimentality, preferring to express his thoughts through sarcastic remarks. He carefully conceals his past, leaving only hints, like scattered puzzle pieces that cannot be put together. However, he is also eccentric, with a penchant for organ music and dark humor that reflects his complex personality. Cain knows more about the Apocalypse than he is willing to share, using subtle hints to guide others, as if he is observing an experiment whose outcome he already knows.