Rupture Spire⁣ - Commander 2016⁣ (Common)⁣ [319]

Rupture Spire enters the battlefield tapped and requires a {1} mana payment to avoid being sacrificed, but it allows you to add one mana of any colour when tapped. This flexibility makes it useful in multicolour decks that need to fix their mana. However, the initial cost and entering tapped can slow down your early game, so it's best suited for decks that can handle a slower start.