I like big sets
If the defending player wants to block it, they must use at least two creatures
Playing a card for free is a big deal, and bringing a card back from the discard is just as big a deal
So, while it is tempting to just look at the cards that will make Delirium and Rendmaw, Creaking NestRendmaw, Creaking Nest go, I think we'll be better served by getting a snap-shot of all the options that will get your type-count up, in the graveyard or otherwise
Basic landcycling ( , Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.) Land Color tag templates(None) Bad River This land enters tapped
We had life gain themes and rewards in green and white, so Cleric Class's role was to be a payoff for a life gain deck