Waterspout Elemental

Pay the one extra blue and the whole board folds: a symmetrical bounce that returns every creature except this one to its owner's hand, then charges you a skipped turn for the privilege. The clause says "all other creatures," so the 3/4 flyer survives the reset and leaves you with the only thing on an empty field. The wrinkle is the order of operations between you and the opponent. You skip your next turn, which means they untap first, redraw their hand, and start redeploying before you can do anything with the window you just opened. The kicker is not really priced in the extra mana; it is priced in that lost turn, which converts a one-sided blowout into a gamble on a clock. The unkicked mode is the floor: a five-mana evasive body with a respectable back end, the gentle baseline that makes the reset a choice rather than a tax. As a piece of design it sits in an early line of symmetrical-sweeper-with-a-catch cards, where the catch is what keeps a swing this large honest. The strong line is to kick it when you can spend the borrowed turn at instant speed (a counterspell held up, a finisher cast on the opponent's own step), so the mortgaged turn still buys you a developed, evasive threat staring down a clear board.