Nissa, Worldwaker [Archenemy: Nicol Bolas]

+1: Target land you control becomes a 4/4 Elemental creature with trample. It's still a land.
+1: Untap up to four target Forests.
−7: Search your library for any number of basic land cards, put them onto the battlefield, then shuffle your library. Those lands become 4/4 Elemental creatures with trample. They're still lands.