Aether Channeler

Mystic Snake set the modern expectation for what a modal blue value creature should offer, and Man-o'-War taught a generation that a blue body bouncing a permanent on entry is worth a card by itself. This folds three of blue's evergreen jobs into one entry trigger and lets the caster read the board before deciding which one to buy: a flying blocker and future evasive attacker, a tempo swing that unwinds an aura or an equipment or resets an opposing threat, or a flat card. What makes the design tight is that none of the three modes is a dead draw. A raw cantrip keeps the floor high when the board is even; the bounce mode turns three mana into a genuine tempo play against decks trying to stick permanents; the Bird token gives an evasive clock and chump-blocker when neither of the others matters. The 2/1 body is the price: it dies to almost everything and does not want to attack into a healthy board, so the value is entirely front-loaded into the enters-the-battlefield choice, and the card is functionally a spell that leaves a fragile creature behind. That framing (spell first, creature second) is what makes it flicker fodder and reanimation bait rather than a card you cast for its combat stats, and it is why the design has aged into a template for how much modality a three-mana blue creature can carry without warping a format.