when nissa, vastwood seer enters the battlefield, you may search your library for a basic forest card, reveal it, and put it into your hand, then shuffle your library.
whenever a land enters the battlefield under your control, if you control seven or more lands, exile nissa, then return her onto the battlefield transformed under her owner's control.
--------------------------------------------------------------------------+1: reveal the top card of your library. if it's a land, put it onto the battlefield. otherwise, put it into your hand.
-2: put a legendary 4/4 green elemental creature token named ashaya, the awoken world onto the battlefield.
-7: untap up to six target lands. they become 6/6 elemental creatures. they're still lands.