I wouldn't say to know to some Tetra Master.. Rare cards dropping from fates, dungeons, etc. Even throw in some craftable cards to give crafters some love. The potential is there for a fun minigame. Win so many matches get special house items or tournaments to win one-of-a-kind items. As long as it stays away from the ever so popular P2W format i.e. spending $100 just to have a chance at good cards.