Jin from Devil's Spice. Devil's Spice. Eventually this leads to MC getting run over by a bus and losing 2 of his limbs and him "becoming a monster." Fast forward to the present, Jin is back and he's a conman. He manipulates MC's only normal friend(girl not in the corruption and death who happens to like MC) into inviting him over. He then sexually tortures her. It is during the sexual torture of friend that we find out that he originally separated from girl after awhile, but after college he met up with her again. Girl felt extremely guilty about what she did to MC. He eventually uses that to manipulate her into a depression that causes girl to commit suicide. In vol.3 he is on the run from MC because MC is sparing no expense to find him, but he's still trying to manipulate others to kill MC. He blames MC for the way his life turned out. At the end of the volume he is betrayed by someone he is manipulating gets thrown into a gladiator like arena as a prisoner where MC happens to be fighting. He then tries to manipulate MC into freeing him and not killing him when he gets out, but MC has a realization "he's human and not a monster so he can lie" and kills him. Satisfying death but he is my least favorite type of person.")