Decanter of Endless Water

Five-color fixing at this rate is nothing new; the reason to look twice sits in the top line, an effect that almost always rides its own dedicated permanent. Bolting a permanent maximum-hand-size lift onto a rainbow rock aims the card at a specific kind of engine: decks that draw far past what they can spend in a turn and would otherwise discard the overflow at cleanup. The rock keeps colored mana flowing to cast the surplus, while the hand-size clause parks everything above seven until a later turn can use it. That makes it a support piece for wheel-and-refill and storm-adjacent shells, one that never draws the cards itself: it removes the discard step's penalty for holding too many. The awkwardness is that each half recruits a different pilot. A ramp deck wants the mana and ignores the storage; a draw-heavy control or combo deck wants the storage and treats the fixing as gravy. Its home is the narrow band of decks that genuinely want both in the same slot, a smaller target than the image of a bottomless decanter suggests.