Animal X: Marcus

Character bio:

The adopted son of Domino, Marcus doesn't remember who his birth parents were due to Domino keeping that a secret from him, the only thing Marcus has to remember from his birth parents is a key that he carries around his neck that belonged to them. Marcus was indoctrinated from birth by his adoptive father to be a merciless cryptid-killing machine, blindly serving Domino and the black dot's cause going under the alias of "Agent M" while wearing his ninja suit to hides his identity while fighting Daniel and Natalie all the while he befriends our heroes in order to gain their trust. however over time he starts to warm up to Daniel and Especially Natalie and begins to question his allegiance to the Black Dot and his "father".

Character drawn in MS paint

Link to story: https://www.wattpad.com/1227468517