Strength of Will

Green protection spells have historically been binary: either your creature survives combat or it doesn't. This one inverts the math. Indestructible handles the survival half, and by removing the lethal consequence of damage entirely, it clears the way for the second clause to do its work: every point that lands becomes a permanent +1/+1 counter. Throw your creature into a wall of blockers and it walks out of combat bigger than it went in; if an opponent points a burn spell at it, that damage cannot kill it and instead swells the body. The window is the point of the design. It resolves at instant speed and lasts only until end of turn, so it wants to be cast mid-combat, after blocks are declared and damage is inbound, so the counters land while the shield is still up. It rewards the fight-style green shells that trade combat math for size, and it punishes any answer that relies on damage rather than exile, bounce, or a minus-toughness effect. Because the counters are real objects on the creature, they persist after the indestructible falls away at cleanup: the body keeps whatever it grew into. A trick that does not merely save a threat but launders an attempted removal spell into a board-state swing.