Nerissa, Songstress Fugitive

Nerissa, Songstress Fugitive can't be blocked.
Whenever Nerissa deals combat damage to a player, that player exiles cards from the top of their library until they exile an instant or
sorcery card. You may cast that card without paying its mana cost. Then that player puts
the exiled cards that weren't cast this way on
the bottom of their library in a random order.