Silkwrap

The mana-value-3-or-less ceiling is the whole conversation here. Earlier white removal-on-an-enchantment leaned on the broad version: Oblivion Ring, Banishing Light, anything that could pluck a creature of any size or even a noncreature permanent off the table. That breadth came with a tax in flexibility and, more often, a higher floor of cost or downside. Restricting the target to small bodies is what buys back the two-mana rate, and it changes what the card is actually for: this is an answer aimed downward, at the early-game threats that decide aggressive matchups, not at the bomb that wins the long game. The trade is honest. Most of the creatures that matter in the opening turns sit at or below three mana value, so they fit under the ceiling; the fatter finishers and anything cheated in above the line walk right past it. The exile-until-it-leaves clause carries the usual enchantment-removal liability, where destroying the Silkwrap returns the creature to its owner, so it functions as a tempo answer with a fuse rather than a permanent one. What makes it worth studying is the discipline of the costing: white has long searched for the cheapest possible catch-all that does not also erase a finisher, and pricing the answer by the size of the thing it catches is one of the cleaner solutions to that problem.