I do sympathise - I have an angelic 8 yr old at the moment but have been a secondary school teacher for far too long to be under any illusions about how quickly it can all change!
My instinct would be to settle down for the long haul and prepare to be very, very patient and very, very firm. So don't let him goad you into argument or losing your temper, but stick to your guns as well - be polite and loving with him, but do not give in until he toes the line with regard to behaving in an acceptable manner: no x-box, no phone, no whatever.
Easier said than done, I know, to rise above the abuse and the aggression, but if you can remain constantly calm and firm, he might eventually tire of trying to provoke you into a loss of control where he can feel that he has won/is justified in his behaviour.
So if he says: 'Everyone is laughing at me because I haven't got x game', just reply 'Are they? That's a shame.' It doesn't give him anything to engage with or argue with.
The verbal and physical abuse is harder - I am not sure how I would deal with that because obviously, he needs to be very clear that that is NOT something that can be ignored. You could talk to him about the penalties for assault - how it is a criminal offence, I suppose but I don't know what I'd do, tbh.