Ichor

Also referred to as engrammatic matter or mnemonite, ichor is a kind of amorphous material formed by infusing tangled soulfire. It naturally encrusts surfaces over time if they are exposed to any amount of infusion, as permeability gradients slightly bunch up incoming soulfire, which is then slowly infused by the local conscious pressure.

Ichor can be intentionally produced by infusing soulfire spun to weave an engrammatic structure, and such deliberately produced ichor is often used as currency. However, infusing spun soulfire takes significantly more intention then its unspun counterpart, which further scales rapidly with volume and spin count. This means that actually producing ichor is a notable mark of phlogistic strength.

Aside from it's rather negligible ability to serve as engrammatic mass, ichor also has the notable property of having completely manipulable mechanical properties, which is why the corpora of many non-biological persons are formed of it, and where its name is derived from. Before the nature of ichor was understood, it was believed to be the blood of demigods, since cuts against such powerful phantasms would loose the ichor which composed their body, causing it to liquefy and evaporate.

If no action is taken to generate an imaginary surface, its color and appearance is dependent upon the producer and their intentions. Generally speaking, phlogistically denser ichor is more colorful, and has many river-like veins flowing along it. Regardless of rigidity, it has a sheen like polished stone, and feels smooth to the touch.

Soulplane Projection

Beyond simply producing ichor, a feat of strength and skill is maintaining and manipulating ethereal ichor: stretched so thin yet remaining so strong as to hold back reality and substitute a soul plane. Within such a construct, often called a soulplane, the engram encoded in the ichor is local law; this could be a certain space-time metric, an immersive memory, or various other phlogistic effects. However, the more complex the encoded engram, the more difficult it is to stretch the ichor without tearing it. Thus large or complicated soulplanes are yet further difficult to produce. This is made worse by the fact that as more soulfire is contained within the plane, the ichor barrier must be made larger.

Once inside a projected soulplane, escape is extremely difficult for any who are not rather familiar with ichor manipulation themselves. Spatially, a soulplane is often projected with a differing volume density and toroidal topology, thus the only way out is to directly attack the composing ichor. This is tantamount to rending the fine threads of reality, a predecessor of the same skill which allows one to deploy a soulplane in the first process, and one that is resisted simply by strong ichor.

Notably, the actual soulplane--which is the interior conscious plane to the soul--is separate from a projected soulplane, which can differ wildly from the creator's actual soulplane, but also may indeed be a distinct copy of it. In fact, soulplanes which constitute an exact replica are often noticeably more durable due to their alignment, at the cost of a fixed and uncontrollable effect based on the user's cognition.