Voice of Resurgence

Whenever an opponent casts a spell during your turn and when this creature dies, create a green and white Elemental creature token with "This token's power and toughness are each equal to the number of creatures you control."

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6o2o5t0oh1pb1hjia0wzjs.