Zafira, Elderstorm Rider

+1: Look at the top three cards of your library. You may put one of them into your hand and one of them into your graveyard. Exile the rest.
-3: Exile target creature or artifact with converted mana cost four or less. Each player exiles the top card of their library.
-6: Cast all cards you own exiled with Zafira, Elderstorm Rider from exile without paying their mana costs.