Grixis Illusionist

A one-mana fixer that never makes mana directly: the tap ability rewrites the basic land type of a land you already control, so a land tapped after the change produces mana of the type you named. That indirection is the entire design. It only ever touches your own lands, which means this is fixing for you, not a service for the table, but the more interesting consequence is everything that cares about land types rather than mana. Anything keyed to whether you control a Swamp, an Island, or a Mountain can be switched on by a single activation, turning a corner of color correction into a setup tool for off-color payoffs that have nothing to do with producing mana at all. The 1/1 Wizard body keeps the trade honest: it is cheap, it dies to a stiff breeze, and it fixes one land per turn rather than dumping a dual onto the table all at once. That is the bargain the whole lineage of land-type manipulators makes, swapping the reliability of a tapped dual for repeatability and a creature on board. It sits in an odd corner of design where the creature does not ramp or produce mana but reshapes what your existing lands are, and the payoff comes from the relabeling, not the resource.