Urborg, Tomb of Yawgmoth is by far the best way to turn all our lands into swamps, but if you dont want to fork over $50+ then you can run Blanket of Night instead
Sacrifice after IV.) I, II, III Until your next turn, whenever you cast an instant or sorcery spell, target player mills cards equal to that spells mana value
Facilier and Lefou - Instigator
As for playgroups, sometimes you just need a bundle that has cards that were meant to play together and the Bloomburrow precon bundle is full of powerful tribes that offer a unique tabletop game
Zendikar Rising Set Booster Pack $5.99 US Shipping Only Due to export restrictions, this item may only be shipped to addresses in the United States, APO/FPO addresses, and Puerto Rico