Artificial Evolution

Tribal-type editing as a one-mana instant, and the rules-text precision is the whole interest. Where most type-matters effects add or subtract a creature type, this one performs a find-and-replace on a spell or permanent's existing types, and the change lasts indefinitely rather than until end of turn. That opens two distinct lines of play that share a card. Defensively, you can rewrite an opponent's tribal payoff so it stops seeing its own team, or redirect a creature-type-targeting spell into a whiff. Offensively, you can retype your own creature on the stack or already in play to dodge a removal spell that names a type, or to qualify for a lord or anthem it otherwise misses. The one carve-out, that the new type can't be Wall, is the kind of guardrail that betrays exactly the loophole the designers saw coming: retyping an attacker into a Wall to neuter it. The text-changing class of effect is rare and finicky to template, which is why so few exist; this is the cheapest and most flexible of them, and its value scales entirely with how much a given board cares about creature types. In a vacuum it does nothing, which is the honest cost of a card that only matters when types are load-bearing.