Revised Doctrine

Whenever an opponent casts a spell, if it shares a
card type with a permanent you control, you may exile that spell. If you do, that player may cast a nonland card from their hand without paying its
mana cost.
Then, you may cast a copy of the exiled card.
If a spell you cast this way would be put into exile,
put it into your hand instead.

The old rules were fine—until they weren’t.