Krux, Imperator Bonded

-1: Add three white mana to your mana pool, then exile the top card of your library. You may play it for free this turn.
-3: Destroy up to three non-white creatures with combined power less than your life total. Gain life equal to their combined power.
-7: Create the game emblem: "At the end of each player's turn, put a loyalty counter on Krux."