Arguing - is two-way. You can stop the arguing by setting firm boundaries, then don't argue about them, just repeat the boundary and consequence if broken. Take all emotion out of your responses to Boundary pushing.
Ungrateful - is not uncommon. In terms of Christmas gifts, I would not be gifting surprises at this age. Id give a budget and request he send me a link to what he wants, for me to buy. They won't be ungrateful then. Also teaches elements of budgets and managing expectations.
Not listening - listening is also a two-way thing. Are you listening to him, verbal and non-verbal communication? I'm a firm believer that you have to give respect to be respected. 12 is that transition age where you have to shift away from 'do as I say.. because I'm the adult' towards allowing a degree of ("a degree of", by no means "full" at this age) autonomy to make mistakes, understand consequences and learn from them.
He is mean to his younger sister and just wants to be gaming all the time - both normal. Teach his sister to give him space and leave him alone.
plays the victims and acts like he didn't do anything - in his eyes, being told off means he is the victim. Therefore not an unusual or irrational responce, even tho its frustrating for you. Try not to 'win' and have him 'lose'. Just apply the expected consequences.
started lying a lot - children lying says more about their parents than it does the child. Think about why he lies? Lying is evidently his best option. Why?