Seafloor Debris

One of the Odyssey "debris" lands, built around a sacrifice clause that turns a tapped blue source into a single burst of fixing in any color. The design tension is right there in the activation: the land taps for blue indefinitely as long as you leave it on the battlefield, but the moment you reach for the off-color mana, you give the land up entirely. That makes it a fixer for decks that want to splash, not stretch: you get one perfectly-colored mana when you need it, then you're back to whatever's left. Compared to a permanent dual that keeps producing, this is closer to a one-shot ritual stapled to a land slot, paying for its color flexibility with its own existence. The entering-tapped clause is the second tax, costing a tempo turn on the way in. It belongs to a school of fixing that treats mana correction as something you spend rather than something you hold, where the question isn't "what colors does this make" but "how many times." Here the answer is one off-color, or blue forever, and you choose at most once.