Yavimaya Bloomsage // Channel [92] [Extended Art] [Secrets of Strixhaven: Commander] [Non-Foil]

At the beginning of your end step, put a +1/+1 counter on target creature you control. Then if that creature has power 7 or greater, this creature becomes prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)