Shrine of the Forsaken Gods

The seven-land threshold is the whole engine, and it tells you exactly what this land was built to power. Below seven, it taps for a single colorless: a worse Wastes, a do-nothing that fixes nothing. Cross the threshold and the second mode wakes up, doubling output for spells with no color in their cost. That gate is what pays for the burst: this is acceleration that only arrives once you have already built the manabase that wants it, so it cannot smooth a slow start the way ramp usually does. It is a payoff disguised as a land, the second half of a curve rather than the first. The colorless-only restriction on the doubled mana narrows the target to the decks that care: Eldrazi shells and the big artifact piles where the expensive spells were never going to need pips anyway. The structural ancestor is the old "control X lands to get more out of this one" idea that runs back through cards like Cloudpost and the Tron lands, where a single source goes from trivial to explosive the moment the surrounding count clears a bar. What separates this design is that the bar and the payoff live in one card instead of a pieced-together set, which makes it a clean test of whether your deck has reached critical mass yet. Until it has, you are running a land that does the least; once it has, you are casting the things other decks cannot afford.