Aventurine, High Roller

At the beginning of combat on your turn, Clash
with an opponent. If you win, put a shield counter
on each nontoken creature you control. If your
opponent wins, that player creates two Treasure
tokens. Then each Draw a card.(Each clashing
player reveals the top card of their library, then puts
that card on the top or bottom. A player wins if their
card had a higher mana value.)

Whenever a shield counter is removed from a
creature, create a tapped Treasure token.