Any card can be fused, at any time, and the best part is, you're now told the exact card you're going to get before finalizing the fusion
For example, if Alex has a Slaking CES in the active position and Brittany attaches a tool to her Garbodor BKP or moves a Wobbuffet PHF into the active, Slaking takes precedence as it was activated first
Should you choose to turn Aang back into his front side, you get to swing life totals by eight, draw four cards, and grow Aang
Then exile it.) Sorcery Draw (CTRL to add secondary) Land Land (CTRL to add secondary) Landfall Landfall (CTRL to add secondary) Mill Stubborn Burrowfiend Whenever this creature becomes saddled for the first time each turn, mill two cards, then this creature gets +X/+X until end of turn, where X is the number of creature cards in your graveyard