>>31186656>How should I work towards getting Shaymin?Trading. Enter a few (Theme) tournaments to win a couple of packs/chests and trade your way up. I haven't bought a Shaymin in a while, so I can't tell you exactly how many you need (you will want to post your own offer though; public offers are generally a poor deal).
After you've played for a while, you can always invest tokens into Roaring Skies packs in the shop. It's a long shot, but it's not like there's masses of things to spend tokens on. I just came back after a fairly long break and spent a load of tokens on ROS boosters and managed to pull a FA Shaymin-EX