Kami of False Hope

The Fog effect grew a body. Where a one-shot combat-prevention spell does its work and leaves, this folds the same blanket into a creature you can deploy early, chump-block with, or hold in reserve until the alpha strike actually comes. The sacrifice cost is the whole transaction: you spend the spirit, not a card from hand, so the prevention has already been paid for on a previous turn. That changes the timing math in a way the instant cannot match. A 1/1 on the battlefield is public information, a known blocker the opponent reads before committing, but the choice to swing into it is theirs to misjudge: hold the sacrifice through the declare-blockers step, after the attacker has committed everything, and the Fog still goes off before any damage is dealt. It also chains with recursion in a way an instant never could. Anything that returns a small creature, reanimates it, or tutors it back turns a single combat denial into a repeatable wall against any board that wins through the red zone. The restriction that keeps it fair is narrow scope: it stops combat damage only, so burn, mill, and noncombat effects walk right past it, and the body dies to any removal that would have killed a vanilla one-drop anyway. It is the prevention effect rebuilt as a permanent, with all the deck-construction implications that swap carries.