Waterkin Shaman

A payoff without a plan of its own. The 2/1 body is small enough that it needs the fliers around it to matter, and the trigger keys on a creature entering rather than attacking, so the bonus is a fleeting until-end-of-turn pump rather than a permanent anthem. That timing dictates how it plays: it wants a curve that drops evasive creatures on the same turns you plan to swing, converting a go-wide skies deck's tempo into a bit of extra reach on this one attacker. Note that the ability cares only about the flying keyword, not any creature type, so the enabler pool is any winged thing you can play, and each one stacks another +1/+1 within the turn. That rewards flooding the board over building it slowly: a ground body that hits harder the more the air above it fills. Left alone it trades down to almost anything; surrounded by the creatures it counts, it becomes a repeatable, if temporary, closer that punishes an opponent for leaving the ground undefended while the real threats fly overhead.