Obelisk of Naya

Tap it for mana the turn it lands, no enters-tapped clause to surrender a beat, and it will hum along under any three-color base committed to red, green, and white. That is the entire pitch, and it is built around an era's obsession with shard and wedge identities, where an artifact's worth was inseparable from the color trio stamped on it. The lineage runs through the early mana rocks and the Diamond cycle, but where those produced a single fixed color, this trades reliability for a three-way choice locked to red, green, and white. The triad is the whole bargain. It contributes nothing to the spell count or the board, and at a single source for its cost it is slow acceleration: the rate is poor next to a cheaper rock, but it still ramps, adding a permanent source that lifts your available mana on every subsequent turn while smoothing which colors that mana can be. The absence of a tapped clause is what keeps a greedy three-color base on curve, letting the source come online immediately rather than costing a turn the way an enters-tapped rock would. As fixing it is honest and unglamorous: a colorless source that means nothing outside its three colors and does exactly one job for the decks committed to all three. It is the cleanest expression of the idea that a mana rock could be designed for a color grouping first and a deck second.