Prowess triggers when you cast a noncreature spell, while the spell you just cast only checks whether Ferocious is true as it resolves. Since the trigger goes on top of the spell and resolves first, this generally works out well for you!
…and knowing is half the battlefield
Prowess triggers when you cast a noncreature spell, while the spell you just cast only checks whether Ferocious is true as it resolves. Since the trigger goes on top of the spell and resolves first, this generally works out well for you!