Namora, the Sea Queen

Power-up is a keyword that hands a permanent one enormous activation and then bolts the door behind it, and this Merfolk leans on that one-shot constraint to justify an unusually top-heavy payoff. The base is a cheap evasive body, but the engine sits behind : a counter to lift her out of common removal ranges and two 1/1 Merfolk to seed a board in a single beat. The parenthetical rider is where the design tightens. If she entered the battlefield this turn, the cost drops by her mana cost, so the intended line is to cast her and immediately fire the ability the same turn, discounting a nine-mana sequence into something a fast mana base can front-load. That "reduce the cost if she entered this turn" clause is a hard timing gate: hold her back and the discount evaporates, and because power-up can be activated exactly once, there is no trickle to bank across turns. She is built to be a Merfolk anchor who arrives, converts a stack of mana into a wide board and a hard-to-kill flier, and then settles in as a 3/4 with a counter on her and an ability already spent. The whole card is a bet that one large, timing-gated burst rewards a deck more than a small repeatable value you lean on every turn: commit at the right moment, or the payoff shrinks the longer she waits.