Rosa, Resolute White Mage
The lifelink lands before attackers are declared, which is the entire trick: the counter and the lifelink land on a creature you fully intend to swing with, not one you're holding back on defense. That timing is the engine. The same creature that grows, gains life on damage, and still serves as the beatdown does all three in one motion, and the effect renews every turn you attack: counters stack while the lifelink refreshes combat after combat, turning a single threat into a lifegain win condition. The 2/3 body and the Reach point in the opposite direction, toward the ground she was built to defend: not a large frame, but one that survives a swing and pulls fliers out of the sky while the counters pile up elsewhere. White has always had lifegain and always had counter-based growth; folding both into a repeatable trigger that also feeds the attack step is a tidier package than the color usually gets on one card. The restriction that pays for the value is the targeting: one creature per turn, on your turn only, so she rewards a board you are already committed to pressing forward with rather than a defensive stall. She reads as a modest midrange creature and plays as a slow-rolling advantage engine that only pulls ahead when you keep swinging.
