The Crowd Goes Wild

欢呼震天 (The Crowd Goes Wild) (zhs)

Sorcery (CMC 1)
Assist (Another player can pay up to of this spell's cost. You choose the value of X.)
Support X. (Put a +1/+1 counter on each of up to X target creatures.)
Each creature with a +1/+1 counter on it gains trample until end of turn.