The Zhargevian Potential Scale

The Zhargevian Potential Scale, as devised by Ilithiran' Imperial Scholar Nominakir Bartholomew Zhargev, is widely applied and an almost universally valid scale to judge and classify the human Kathast and relate it to four levels of aptitude and potential as devised by the man himself.

The Scale is notorious for being one of the most decisive factors in acceptance into any major school, academy or otherwise magical institution, though there are institutions that replaced this scale with a means of classification of themselves.

1. Level 1 A Kathast of the first stage is by far the most common of all types of Kathast in all humans with Aetir aptitude. It makes up approximately 99% of the Aetra population and comes in many shapes and forms, yet is defined by the commonality of a Tar-Canal with two pairs of side openings which work somewhat like valves funneling undefined Aetir into the canal in order for it to be channeled into the Nuclear Definition Chamber. A first stage Kathast furthermore **lacks** an Aetirnucleus in the center of the Nuclear Definition Chamber, which practically forbids an Aetra with this Kathast to supercede the first circle, making learning the fourth Dialect of Tainen'ar virtually impossible.
2. Level 2 A stage two Kathast is much more rare than a stage one Kathast in comparison, as you may eventually be able to find one singular cultivator within a hundred if the odds allign. This Kathast is defined by three pairs of opening apertures on the sides of the Tar-Canal, and even has an intermediate Aetirnucleus, lifting many of the fixed limits of a stage one Kathast, allowing Aetir to be funnelled, channelled and defined at a much faster rate than otherwise possible. A stage two Kathast allows it's wielder to practically soar to impossible heights, not witholding anything, and giving the ability to overcome any bottleneck in theory.
3. Level 3 A Kathast of the third stage already counts as an extreme talent, and one may be hard-pressed to find a single one in a crowd of ten thousand Aetra. It is defined by the maximum possible opening pairs to the Tar-Canal, so four, and enables the Aetra to funnel and channel unbelievable amounts of Aetir simultaneously and thus control it. Through the resulting extremely high concentration of Aetir ever-present in the canal and the Nuclear Definition Chamber, an advanced Aetirnucleus can be found at it's center, increasing the speed at which an Aetra wielding this Kathast is able to cultivate his reserves of Aetir and his knowledge of Tainen'ar and thus becomes stronger.
4. Level 4 The stage four Kathast is the last and also the best, most developed known phenotypical Kathast and thus the last level of the Zhargevian Potential Scale. The Kathast is not able to easily be physically told apart from it's stage three counterpart, though, the differences solely manifesting in it's capacity to utilize a more complicated Aetirnucleus to increase the Aetir capacity of said Kathast. Through it's inherent spatial laws and the consequential aptitude for spatial laws of the wielder of the Kathast, an Aetra is able to have a natural substantiallly larger reserve of Aetir and channel and control it with ease, elegantly breaking through any bottlenecks presenting itself to the cultivator.