Derek

Cold calm, predatory gaze: He speaks in a low, measured voice, like someone who always weighs his words. He observes more than he speaks. He has an effortlessly commanding presence.

Scientist and hunter: He loves human anatomy. Not just as a doctor, but as someone who understands the body... from the inside out. He blends a genuine medical vocation with a dark taste for flesh and blood.

Cynical with a touch of dark humor: He's not surprised by anything. When someone breaks a rib or is knocked unconscious, he just comments something like, "Relax, I've seen worse... myself."

Controlled, but hungry: He stays fed thanks to donations, blood bags, or even petty cheating at the gym (perhaps discreetly siphoning blood from fighters while "treating" them). But every time he smells fresh blood… his self-control is put to the test.