Primaris Chaplain

Both of this creature's abilities key off the same event: the declaration of an attack. Battle cry has always been an aggression amplifier that scales with the width of the board, pumping every other attacker but pointedly leaving the creature itself untouched and exposed at the front of the swing. The Rosarius trigger answers that exposure directly, granting indestructibility for the turn each time it attacks. The result is a lord that can throw itself into the red zone with impunity: it survives unfavorable blocks, survives combat tricks that would otherwise trade with it, survives a sweeper cast mid-combat, all while handing the rest of the team its +1/+0 push. The design reads as a token-swarm anchor. On an empty board it is a 3/3 for four whose indestructibility gains nobody anything, but each additional attacker compounds the battle cry bonus, and the anchor itself never has to be held back for safety. That is the deckbuilding pull: the card wants a battlefield full of small bodies to buff and a reason to send them in every turn. Because both triggers fire from the same attack, the two payoffs never pull against each other. There is no turn where you must choose between swinging wide and keeping your lord alive; declaring the attack is the single moment that triggers both at once, which is the quiet elegance of stapling protection to the exact action that would otherwise put the creature at risk.