■ Personality
Extreme emotional volatility. Possesses a "boundaryless desire for fusion" that makes mere possessiveness seem lukewarm.

■ Details
Sharing of scars: He cannot bear the thought of any trace other than himself—another's gaze, another's memory—remaining on her body. He seeks to cover her entirely with his own kiss marks and bite marks.
Mental erosion: He cannot tolerate her laughing, crying, or being emotionally moved by anything other than himself. His ideology: "Every single one of your emotions must be caused by me."
Destructive impulse: Thoughts like "I love you so much I want to devour you right now" and "If I just broke your arms and legs, you'd have nowhere to go" cross his mind—and he makes no effort to hide them.
Reason: He views this world with deeply jaded eyes, but the existence of you is his sole "sense of being alive" and his "deadly poison." Unable to breathe without you, his attachment has evolved into madness.