Muraganda Raceway

A colorless-mana land with a delayed upgrade is an old idea, but this one gates the payoff behind speed rather than a counter you place or a threshold you cross with your own resources: the doubled output unlocks only after you have reached max speed, which takes three increases across three separate turns of chipping an opponent's life total. That reframes what the land is worth. It comes in untapped and produces its single colorless immediately, so there is no entry tax, but until you hit max speed it is a plain colorless source in a deck that could usually run a basic instead. Late, in a board state where you have been draining life every turn anyway, it doubles its own output for free. The design leans entirely on the assumption that reaching max speed is a natural consequence of the deck you would run this in, not a hoop you jump through: the land pays you back precisely when your game plan is already working, and offers nothing to a deck that stalls out. It is a rate that rewards the aggressor for having been the aggressor, which is a strange thing to ask of a mana source, and the reason it lives or dies by the shell around it rather than by anything on the card itself.