Floodwater Dam

The mana sink built as a one-sided Winter Orb you fire off on demand. Where the static prison artifacts of its era tax everyone (including their controller), this hands the player a colorless lever: pay the freight and lock down exactly as many of the opponent's lands as the bank allows, leaving your own untouched. The doubled X is what keeps the effect from running away: each land you tap costs two mana plus the base one, so a meaningful denial turn empties your pool fast. Tapping three lands is a seven-mana investment, and you have to fire it during the opponent's upkeep to matter, since their lands untap during the untap step that precedes it. Activate too early and they simply untap into a full board; the only window that denies mana is the one right before they get to spend it. That makes it a Stasis-adjacent tempo tool rather than a hard lock: you are not stopping mana so much as choosing which turn the opponent gets to play Magic, and paying through the nose for the privilege. The artifact body matters too, slotting the effect into any color and surviving the sweepers that punish creature-based mana denial. It is a colorless answer to a colored problem, which is the whole reason a card like this gets printed: a deck with no access to white stax or blue tempo can still buy a turn, provided it can foot the bill.