Wynners Circle Games
There is a sealed tourney system on their product page. If I remember right you come to the table with sidekicks, 2 action cards and 4 character card with max 3 each. Then you buy 10 boosters and fill the rest out. Switching out the characters you brought if you want to.
Yeah that was the constructed-sealed format I mentioned. I think that format will make the stronger cards even better. Obv that's a guess seeing as how I'm still new to the game.