Sink into Takenuma

Sweep was the mechanic's attempt to turn land drops into ammunition, and this is the cleanest read on the deal it offers. The cost is paid in tempo: every Swamp you bounce is a turn you spend replaying lands instead of developing a board, and the discard scales exactly with how much of your manabase you are willing to dismantle. That makes it a wholly different animal from a flat-rate discard spell like Mind Rot. A standard hand-attack effect is priced once, at casting; this one is priced again at resolution, in the mana you have to rebuild over the following turns. That double pricing is the entire idea. The ceiling is a one-sided hand-emptying that no fixed-cost discard spell can match, but reaching it means hollowing out your own ability to act. It plays best not as a midgame haymaker but as a parting shot, the spell you fire when your lands have stopped earning their keep and you would rather convert them into the opponent's empty hand. It is also self-limiting in a way most discard is not: a player already in topdeck mode loses nothing to it, so the window where it lands as a backbreaker is narrow and front-loaded. A symmetry-of-resources idea more than a removal-style answer, and one that rewards counting turns rather than counting cards.