Jeweled Lotus

Black Lotus with a leash. The trade is exact: the same explosive three-mana ritual off a zero-cost artifact, but every point of it can only pay for your commander and nothing else. That restriction is the entire reason the card can exist in a singleton format built around a permanent that lives in the command zone and never rots in a hand or a graveyard. Because your commander is always available, the mana is never dead in the way a color-locked ritual usually is: the leash points at a target guaranteed to be castable. The design consequence is a compression of the opening turns. A single-color three-mana commander lands turn one off the Lotus alone; a five- or six-mana one arrives a turn or two ahead of curve, dropping the moment you've assembled the rest of the cost from lands and other acceleration. Its deeper effect is on the risk math of the command zone: it turns an early, expensive commander into a reasonable plan rather than a liability, and it rewards commanders whose impact scales with how soon they arrive. The self-sacrifice and the color-of-choice clause are the giveaways that this was built to slot into any deck without warping its manabase: a universal accelerant that asks only for a commander worth rushing out.