Mists of Lórien

The clever hinge is the phrase "each other nonland permanent with the same mana value." Point it at a single target and you get an overcosted bounce spell; point it at a permanent whose cost is shared across the board and you get a sweeper that leaves your differently-costed permanents alone. That conditional scaling distinguishes it from a plain Boomerang variant: the target you name sets the collection radius, and the width of the effect depends entirely on how the mana values cluster on a given board. Replicate then converts a targeted answer into a scalable reset. Each replicate payment puts another copy directly onto the stack (with its own target choice), so extra blue mana buys you additional mana-value brackets to clear rather than repeat hits on the same one. Cast the spell and pay replicate once and you clear two separate rungs of the curve; pay it twice and you clear three. Note that those copies are put on the stack, not cast, so they never feed "whenever you cast a spell" triggers no matter how many you make. It rewards reading the battlefield as a histogram: not "what do I want gone," but "which mana values, chosen together, sweep the most of theirs and the least of mine." That evaluation happens at the moment of casting and cannot be planned around in advance, which is the tension the design lives on. The floor is a slightly overcosted bounce; the ceiling, on a table full of overlapping costs, is a devastating wave that walks up the curve one replicate at a time.