Crimson Rioter

Swindle — Whenever an opponent casts their
second spell each turn, exile the top two cards of
your library. Until the end of your next turn,
you may play those cards.
{1}{r}, sacrifice Crimson Rioter: Counter target
spell. Its controller discards a card at random. If
it's a nonland card with a different name than
that spell, they may cast that card without paying
its mana cost.