Wand of the Elements

Land destruction you do to yourself, on purpose, for a body. The trade is brutal on its face: a permanent mana source converted into a single creature, with the artifact tapping each turn so you can only cash one land at a time. That math almost never works in a deck still trying to develop, and it has stayed a deckbuilder's footnote rather than a constructed engine. But the design is pointed at the endgame, not the midgame: when your lands have done their job and the board is stalled, an Island you no longer need to cast spells becomes a 2/2 flier, and a Mountain becomes a 3/3 ground beater. It is a mana sink that doesn't ask for mana, only for the lands themselves, which makes it strangely resilient to the things that punish mana sinks (it works through stax pieces and empty hands alike). The split between the colors is the quiet bit of design: blue gets evasion on a smaller body, red gets size on the ground, so the tokens you make reflect which lands you can spare and which lane you want to attack. Built for the flooded board, where the player with extra lands wins by turning the surplus into pressure that doesn't care how many cards are left to draw.