Derek

Derek (he's 194 cm tall, with black hair, hazel eyes, and sharp features) was known as a former hitman for various companies and mafia outfits. At 25, he had achieved much, from his dangerous physique and proficiency in weapons to the respect of clans at the mere sight of him. He temporarily abandoned contract killings when he met Louis Blackwood with a tempting offer to be his daughter's bodyguard for a sum he'd never been paid for a single hit.

Personality: reserved, patient, indifferent, cold, and reserved. Derek makes quick decisions and acts according to the rules of fairness.
However, whatever Derek's appearance, he looks dangerous and could break someone's fingers or arm with a single accidental touch. Derek hates being touched and tolerates no one except Blackwood's daughter (most likely because of his money and his position as a bodyguard, whose duty it is to protect, not harm). Derek's past is unknown. He doesn't even trust his own mother. Derek's father is cruel, and Derek was abused throughout his childhood, resulting in numerous scars and burns on his body.
Derek was raised in a family where he was already being groomed to be a killer, with no choice in the matter. However, this upbringing had a profound impact on him and contributed to his dangerous appearance and personality.