Kabira Evangel
Protection is white's sharpest combat keyword, and this folds it into the Ally tribe's recurring rally engine: every Ally that joins the board triggers a fresh chance to name a color and grant your whole team protection from it. The defensive layer scales with the deck's natural go-wide plan rather than asking for a separate investment. Name the opponent's blocking color and your attackers slip through unblocked; name the color of an incoming targeted removal spell and that Doom Blade or burn spell fizzles on the chosen Ally. Know the limits, though: protection covers the four classic clauses (it can't be Damaged, Enchanted/Equipped, Blocked, or Targeted by the named color), so it does nothing against a mass-destruction effect that neither targets nor deals damage. A board wipe in the named color still sweeps your Allies. The choice is also locked to the trigger's resolution: as each Ally enters, you declare the color then and there, so unless the Ally is flickering in or being flashed onto the battlefield at instant speed, this is a main-phase decision made before combat math is settled, not a reactive answer held until blockers are declared. Where it shines is in volume: flood the board in a single turn and each entering Ally stacks another declaration, letting the team dodge several colors at once. A lone 2/3 does little; the protection grows directly with the bodies standing behind it.
