Kaera, Dark Delver

+1: Target player looks at the top card of their library, they may return it or place it on the bottom of their library.
-2: Target player exiles a card at random from their hand, you may play that card for its cost this turn.
-7: You gain an emblem that reads: "Whenever you cast a spell from exile, you may pay its converted mana cost in any colour mana instead."