Ceithir, Elemental Lord

+4: Destroy one card of all colors, you gain 5 life, draw 1 card, bolster 1, and untap 1 land
-7: Shuffle your graveyard into your library. All lands you control turn into 7/7 Elementals with Haste and Trample. They're still lands.
-17: Destroy target planeswalker, you gain 10 life and this planeswalker gets 10 loyalty for each loyalty point on it.