Transmuting is a darkprime magic powered by birch and spruce that allows the mage to physically transform raw materials into essential goods. This transformative magic is primarily used to synthesize sustenance like food, water, and clothing out of raw materials such as stone or air. The Planners keep the existence of this magic a secret from topside Citizens by claiming that massive machines called "transmuters" generate their resources artificially; in reality, the city relies on the enslaved human mages of the Transmuter Legion, led by Morgian, working endlessly to keep the floating population alive.
The magic follows strict rules of conversion: the more complex the desired output, the more complex or larger the required input material must be. Because the magic completely transforms the material at a fundamental level, leaving no trace of the original substance behind, simple outputs like bread or water can be successfully generated from nearly anything, including broken bricks, scraps of metal, or even raw sewage and human waste.
The Planners ruthlessly exploit this power to sustain their sky cities, hiding the enslaved human mages in massive, secret underground facilities like "the Below". Within sprawling, factory-like rooms such as the "Transmuter 2" (T2) building, hundreds of gaunt, hollow-eyed mages sit at endless rows of desks over open troughs, constantly burning birch to meet the Planners' impossible resource quotas. To ensure absolute compliance, the Planners intentionally exploit the highly addictive nature of darkprime magic; the transmuters experience brief moments of euphoric bliss followed by agonizing pain, keeping them entirely dependent on the Planners' weekly shipments of darkprime wood to prevent violent, deadly withdrawals.
The darkest and most horrific atrocities of transmuting magic occurred after the Below's original water-supplying gate broke, forcing the enslaved transmuters to artificially generate the flying city's entire water supply. As quotas continuously rose, the transmuters were worked to the point of magical exhaustion and death, leading to a vile recycling system. When a mage collapses and dies from overusing their power, Wavelight Church guards and fellow transmuters gather around the corpse, chanting a dark ritual—"From flesh to fallen, we all will rise"—before using birch to transmute the dead body entirely into gallons of water. Because of this horrific system, the oblivious topside Citizens are kept alive by unknowingly drinking the literal transmuted remains of enslaved human beings.