I used to main raze/yoru but I'm getting into playing sova more and I need help on how to play him better, does anyone have any suggestions on who I can watch to get better?

I know this sounds stupid, but my friend got 4400 points 3 times in about a month. He has made no purchase nor is there any purchases made with the card. We checked his account purchase history and he got them through codes, but he has not...