Reliquary Tower

The seven-card hand limit is one of the oldest rules in the game, and most decks treat it as a wall they never reach: you spend cards as fast as you draw them. This colorless land exists for the decks that don't. Lift the ceiling and a draw engine stops feeding the discard step at end of turn, which turns a steady stream of cards into a genuine stockpile. The trade is built into the line itself: it taps for colorless only, so it asks for a slot in your manabase without contributing to your colored requirements. That is the whole bargain, and it is a deliberate one. The card is functionally inert until you have a reason to hold more than seven, which makes it a build-around enabler rather than a generic include: it does nothing in a deck that empties its hand, and quietly compounds in a deck designed to refill it. The hand-size clause is also pure upside in a corner case players forget about, since wheel and forced-draw effects that would normally bury you in excess cards instead become pure card advantage when there is no maximum to overflow. It is the rare utility land whose value is entirely a function of the deck around it, asking you to have already built the engine before it earns its place.