Deadly Grub
Vanishing is almost always a tax: the creature is loaned to you at a discount and repossessed when the counters run out, so the sacrifice clause is the bill coming due. This one rewrites the contract. The death trigger only fires if the body dies with every time counter already gone, which means the disappearing act is not the liability, it is the fuse. You want the clock to tick all the way down. The result is a 3/1 you are incentivized to leave on the battlefield doing nothing for three turns, then cash in for a 6/1 token that doubles its power. The inversion extends to interaction in a way few cards manage: an opponent who kills the Grub early, while a counter remains, denies the payoff entirely, so the correct removal play is the fast one, struck before the timer empties. Wait too long and the answer arrives after the fuse has already lit, leaving a shrouded 6/1 in its place. That reverses the usual logic of holding removal for the right moment: here, patience hands the controller exactly what they were building toward. The shroud on the token is the closing note, and it cuts both ways: shroud, not hexproof, so the creature cannot be targeted by anyone, including its own controller. No auras, no equipment, no protective tricks, no targeted pump from your side either, just a body that sits outside the targeting layer entirely. Once it arrives, the ways through narrow to blocks, sweepers, and other non-targeted effects like edicts.

