Aven Redeemer

Damage prevention as a recurring tap ability is one of white's oldest defensive idioms, and this is the workmanlike version: a flier that taps to shave two off any single instance of damage, every turn, on any target. The repeatability is what separates it from a one-shot prevention spell; what limits it is the two-point cap and the tap cost, so it answers a single attacker or burn spell per turn and nothing more. Bundling the ability onto a 2/2 flier is the design hedge: even when the prevention is irrelevant, the body still attacks in the air and blocks something. In the Bird Cleric line it reads as a defensive support piece, a creature meant to keep your other threats and your life total intact while it chips in for two through the air. The era it comes from is the context: a set built entirely around creatures had to load every effect onto a body, so a repeatable prevention valve lived in the combat zone rather than in the spell slot where it would more naturally sit. That constraint is exactly why a card like this exists in the shape it does, and why the prevention got the modest two-damage ceiling rather than a swingier number.