Quirion Elves

A mana dork that fixes as well as it ramps: the second tap ability turns a base-green body into a two-color filter, locked to whatever color you name on the way in. The choose-a-color-on-entry clause is the friction that prices the off-color mana, since you commit before you know what you will draw. That puts the value with decks that already know which splash they want to support rather than greedy piles hoping to fix everything. Against a plain green accelerant like Llanowar Elves, the upside is the off-color mana; against a true rainbow filter, the cost is being pinned to one chosen color from the moment it resolves. The body is the obvious liability: a 1/1 that taps for mana dies to nearly everything, so the design leans on landing early and surviving long enough to matter. This sits early in the long line of two-mana Elf accelerants that double as color fixing, the template later cards would refine by making the color choice flexible or by bolting it onto a sturdier creature. It marks the point where green's mana dorks began doing a splash deck's fixing work on top of acceleration, asking the builder to declare a plan rather than handing out freedom.