Multani's Harmony

Turning any creature into a five-color mana source for a single green mana is an elegant piece of fixing, but the cost it pays is the most fragile in the game: it ties the mana to a body that dies to every removal spell, every blocker, every wrath. The card answers a problem green has always nursed, color access for splash-heavy or domain-style builds, and answers it on the cheapest possible curve. The catch is structural. Unlike an artifact mana source, an enchanted creature is exposed to two card types' worth of removal, and a two-for-one is built in the moment anything kills the host: the Aura dies with it. That exposure is what keeps the rate honest at one mana. Note the limit on what the host can be: because tapping is the activation cost, a creature with its own tap ability gains less here, since it can spend that single tap on only one ability per turn. The natural target is therefore an otherwise idle body, a chump blocker, a vanilla beater, a token, anything that was not going to tap for value on its own. As a green Aura that grants utility instead of stats, it sits in a small lineage of effects that treat creatures as infrastructure rather than attackers, asking you to read your board for what it can produce rather than what it can swing for.