My demon child

So recently I've adopted a demon child hes got a circle head, 5 finger, 2 toes, no knees, round eyes, a pig nose not a big nose a pig nose, he's got a big belly, long arms, fat lips, eye lashes, little ears, a long neck, small feet, long hair, big thumbs, eyebrows, curly hair, horns (that's why he's a demon), tail, and surprisingly a halo, not the game made by Bungie but an actual halo, and he's had some trouble in school. First of all hes been a bit of a bully and he's only in sixth grade. And second of all from what I've heard, along the with the principal's office visits, he's beaten up 6 kids, stolen 6 pencils without given them back, and cheated 6 times on different tests. I don't know what's gotten into him, sure he has been a troublemaker, but not like this, well not a lot like this, OK maybe not exactly like this...yeah he's been like this before. And I don't know what to do he's having a rough time in school keeping his grades up and has only made a few friends most of them I'm not too sure about but the parents are nice. Can anyone help me? If you can post suggestions in the comments about how to deal with this I'm obviously not an amazing parent or "super-dad" so if you guys have dealt with a demon child and/or a misbehaving child tell me how to deal with said child. Thank you.

This is Algoro that is his name he is male although he does look female he is male.