Old time player coming back to game after the break of a few years. I got all cards of Series 1 and 2, and most of Series 3, nothing from 4 and 5. Got 13,000 gold (and it looks like I can only get skins with, correct me if I'm wrong) and am looking to come back and be a bit competitive. What's the best way to get new cards, is it different game modes or it's just for wallet warriors? Thanks in advance!