Im sure this guy has a mental disorder, but i dont know what it is?

its hard to describe, but he gets really angry and shows violent behaviour. hes been beating his girlfriend for a long time but just recently hes finally been arrested for it. the thing that is really weird is that he seems to deny things that really happened, and seems to be living with his head up in the clouds most of the time. for example hed beat his girlfriend up and then afterwards sais he didnt hit her and she doesnt know what shes talking about. then he goes and tells her that shes going crazy and that shes delusional, which messes with her head. i know he beats her because iv seen it for myself and so have the police. after he got arrested he posted stuff on his facebook that he cant wait to see "my girl" again, even though she made it clear she was breaking up with him. its like he just avoids the truth and constantly living in la la land! hes also extremely selfish, he will find anyway to get what he wants and manipulates as much as he can to get it.he knows that she is miserable with him but he wont let her leave him. after he got arrested he turned the whole story around to make everyone feel sorry for him, and it worked! he is also lying through his teeth about what really happened that night, saying that he didnt really beat her up. his parents and everyone around him seems to believe him even though the cops told them what they saw. he is completely crazy, he even tried to kill himself infront of her once when she told him that she was gonna leave him, so she'd stay. he then pulled the knife against her and threatened to stab her. its like he cant go without getting what he wants, if he wants something he has to get it, and hes a master manipulator. do you have any idea what disorder this guy has? do you think he might be a phycopath or something? i considered it but then sometimes he can be really empathetic and understanding.