Hirio, Silent Spellstealer

Whenever Hirio deals combat damage to a player, target instant or sorcery card in your graveyard gains flashback until end of turn. Its flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)
{t}: Search your library for an instant or sorcery card, reveal it and put it into your graveyard. Then shuffle your library.