Taya, the Spell Swindler

Creatures with power 1 or less can't be blocked
and gain "Whenever this creature deals combat
damage to a player, that player discards a card."
Whenever an opponent discards an instant or
sorcery spell, exile it. For as long as that card
remains exiled, you may cast it and you may
spend mana as though it were mana of any type
to cast it.