Arashi, the Sky Asunder

Channel is the design idea that lets a creature double as an answer it never wanted to be, and this is its cleanest green expression: a 5/5 Spirit that pressures the ground, or, if you would rather not commit it to the board, a discard that scales an X-damage sweep across every flier in play. The constraint that keeps both halves from being a strict upgrade is that both only ever hit fliers. Every mode only ever touches creatures with flying, so the card is anti-air and nothing else; against a fliers-light board the body is a 5/5 beater whose activated ability has no legal target, and the pitch is dead. On the battlefield it is a repeatable, mana-hungry flak gun, taxing opposing flock strategies one creature at a time. In hand, the Channel mode is an activated ability, not a cast spell, so it fires at instant speed: a green flier-sweep you can hold for the attack step, paid out of a card you discard rather than cast. That instant-speed clause is the load-bearing piece. Green is the color that already owns anti-air interaction through reach and fight effects, but those usually demand a creature on the board or a card in hand resolved on your terms; Channel folds both a permanent threat and a reactive sweep into the same piece of cardboard. The sweeper version costs you the body and a card; the body version costs you the sweep. You commit to one and surrender the other.