Void Mirror + Possibility Storm

Void Mirror

Possibility Storm

How it works

1. Whenever a player casts a spell from their hand, Possibility Storm triggers, exiling the spell and allowing the player to reveal cards from the top of their library until they reveal a spell that shares a type with the exiled spell, and cast it without paying its mana cost.
2. If the player chooses to cast the spell, Void Mirror triggers, countering that spell since no colored mana was spent to cast it.