Crown of Vigor

Green's entry in the Crown cycle rides the same dual-mode chassis as its four siblings: a permanent stat boost you can liquidate for a one-shot tribal pump when the math demands it. The split is the whole reason the card exists. Left in play, it is a modest +1/+1 that keeps a creature one step ahead in combat. Sacrificed, it converts that single buff into a team-wide swing keyed to creature type, turning one enchanted body into a payoff for the whole shared-tribe board. That second mode is why it belonged to a creature-type-obsessed era: park the Aura on a Goblin or an Elf, and the sacrifice finds every other one in play to push a stalled race over the line at instant speed. The design answers the standard Aura liability (card disadvantage, vulnerability to a single removal spell) by making the enchantment a tempo investment you can cash in on your own terms before it gets two-for-oned. It asks the deck to commit to a tribe wide enough that the sacrifice reaches several bodies, and that deckbuilding demand is exactly what pays for an effect cheaper and broader than a comparable instant would be.