Reject Imperfection is a uncommon Instant card from Phyrexia: All Will Be One (ONE), collector number 67. Current market price: $0.32 (foil $0.34), TCGplayer market prices via Scryfall.
Counter target spell. If that spell's mana value was 3 or less, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)