You then use Omni-Changeling to copy Marang River Regent, creating an infinite loop of Marang River Regent triggers and North Wind Avatar triggers
The deck then adds a number of different effects that benefit from Venturing, such as Varis's effect to create tokens, Hama's doubling of room triggers, Cloister gargoyle's buff, etc
I think the stock list does a good job of making sure we can trigger Nymris basically at will, and while that is fine and the deck plays a lot like the kind of deck I like to play in those colors, I really like the idea of using my graveyard as a second hand
The creature side of things is Questing Druid, a two-mana green 1/1 that reads: Whenever you cast a spell that's white, blue, black, or red, put a +1/+1 counter on Questing Druid. In the right deck, this card isnt just card draw but a terrifying threat, as it could grow absolutely massive fairly quickly