Quote Originally Posted by Megadeus View Post
Creature decks cannot interact on the stack so they cannot defeat an instant or sorcery.
So let me get this straight, Teeg down and Storm literally cannot win (g1). Storm packs Pyroclasm (g1), and it helps them win (b/c +1 storm count???)...and casting Pyroclasm continually and completely invalidates the entire capability of hatebear deck to win? Don't get me wrong, if Pyroclasm had some kind of "epic" mechanic where it kept firing every single upkeep I'd agree - alas it does not.

This kind of card evaluation is a problem in legacy. You cast Decay: doesn't matter. They cast CB: you lost (until you find the answer). In the same way Storm finds Pyroclasm, they aren't winning. Hatebears finds Teeg and Storm just lost. You're forcing Storm to play removal based magic, but will never be forced to play stack-based magic yourself.