Yes, you can tap a treasure without sacrificing it
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Rikku, Resourceful Guardian allows you to force a creature through your opponents' blockers, as well as steal counters, and Lulu, Stern Guardian protects you by putting stun counters on your opponents creatures, as well as proliferating to keep them around
Since the deck already has a lot of ways to play lands from the graveyard, and with the addition of Loam, Seismic Assault and Molten Vortex add a solid level of inevitability and the ability to clean up a board state full of smaller utility creatures and tokens
First, though, I think it is necessary to define a few in-game concepts that will help you wrap your head around the complex puzzle that is figuring out your best path to victory