Mind Sludge

Hymn to Tourach hands a control player a discount and a coin flip: two random cards stripped for two black mana. This takes the opposite road, scaling its theft to the one resource a dedicated mono-black deck already overbuilds. Every Swamp you control becomes another card pried from the opponent's hand, which means the spell is at its weakest when you most need it (a stumbling early game) and at its most brutal when you least do (a flooded late game where you have already won the resource war). That backloading is the honest cost: it asks you to commit to a Swamp-heavy black manabase and then earns nothing until that commitment matures. The ceiling, in a deck running ten or more Swamps, is a one-card Mind Twist with no life payment and no randomness, scything an entire hand in a single sorcery. The floor, when nonbasics and dual lands crowd Swamps out of your own deck, is a mediocre Mind Rot. What makes the card unusual is where it puts the reward: most color-devotion payoffs count black pips on the permanents you already have in play, but this one pays you for the Swamps you laid turns ago, asking nothing extra at the moment of casting and everything of the deckbuilding that came before.