Fortunately, Master Humboldt had mentioned a detail: "When transferring a Soul into a vessel, one must also consider the issue of affinity. For Casters, plant-based stand-ins accept a Soul more readily than earthen ones. As a Caster proficient in the Natural System, you cannot use this Magic to transfer your Soul into a Mechanical Body unless you create it yourself."
No matter how powerful a Caster was, they couldn't compare to the Primordial One, who could broadcast Its Soul across the entire domain of existence. A Caster's simple transfer, by contrast, came with numerous restrictions.
However, the fact that affinity affected the transfer inspired Rorschach. In his previous life, a common purification technique involved passing a mixed gas through an adsorbent. The separation was achieved by leveraging the varying adsorption capacities of each substance.
