Vermiculos

Every swing this Horror takes depends entirely on what crosses the battlefield after it lands, never before. The +4/+4 fires only when an artifact enters while it is already in play, and the bonus lapses at end of turn, so a hand already empty of permanents to deploy does nothing for it. That inverts the natural rhythm of an artifact deck: instead of accumulating cheap colorless permanents and letting them snowball into lasting value, you want to hold deployment back and dump several in one window, stacking pumps before damage. In an environment dense enough that a dozen or more cheap noncreature permanents per deck was unremarkable, the trigger could fire multiple times in a turn and turn the 1/1 into a real threat. The catch is durability: the swing is enormous but vanishes, so each combat becomes a wager on how much you can drop right now rather than how much you have already drawn. It sits in an uncomfortable middle, neither a beater that stands on its own nor a true value engine, dependent entirely on the tempo of deployment. As design it belongs to the first wave of cards that used "an artifact enters" as a trigger condition, a hook later refined into sturdier shapes; here it is bolted to a fragile body that punishes any turn the artifacts stop coming.