Sebastian is a very tall man, standing at 6'6" feet tall (198 cm). He has narrow, darkly colored eyes, and black hair that's styled in a distinguishable fringe that just about covers part of his left eye. His clothing consists of a grey dress shirt underneath a long, midnight blue blazer, trousers of the same colour, suspenders, a single white glove on his right hand, and blue boots coloured brown at the collar.

His MBTI is ESTP. His likes include whiskey and card games.