Aperture and Primeval Essence

The aperture is the reason cultivation has an economy. A Gu Master does not draw on willpower or on the world at large. They draw on a finite pool whose size and recovery speed depend on talent, and fights turn on who still has essence left when the other does.

Opening the aperture

The aperture is opened in a ceremony rather than through private practice. In the Gu Yue clan this is the Awakening Ceremony. Youngsters attend it at age fifteen, and the ceremony opens the aperture while measuring natural talent at the same time. A child who can walk far enough leaves as a rank one Gu Master. A child who cannot leaves as a mortal, without that talent, for ordinary clan life. ^{ch. 4} That outcome is the ceremony’s result, not a permanent law of the world: later text names Man Triumphing Heaven Gu, which can force-awaken an aperture for a mortal who had no cultivating talent. ^{ch. 274}

A Photo-audio Gu recording of that same ceremony is later shown to Fang Zheng, Tie Ruo Nan, and Gu Yue Bo. In the recording, Fang Yuan is among the youths walking the flower sea. ^{ch. 180}

Natural talent, grades A to D

Talent is graded on a four-step scale from A down to D. ^{ch. 4} The Gu Yue ceremony measures it by how far the child walks through the flower sea. Below ten steps means no cultivation talent. Ten to twenty is D grade, twenty to thirty C grade, thirty to forty B grade, and forty to fifty A grade. ^{ch. 5}

What the grade governs is the aperture: how much of it the primeval sea fills, and therefore how much essence the Gu Master holds and how fast that essence recovers in practice. ^{ch. 7 ch. 22} The academy elder states the sea by layers. D grade fills about two to three layers and usually stops at rank two. C grade fills four to five layers and usually stops at rank two, with a small chance of rank three initial stage. B grade fills six to seven layers and can reach rank three or four. A grade fills eight to nine layers and can reach rank five. ^{ch. 7}

Fang Yuan’s ceremony result is C grade. Inside his aperture the sea stands at forty-four percent, which the text names as the limit of that C grade measure. ^{ch. 6} He walks the demonic path. He states eternal life as the goal worth pursuing. ^{ch. 464}

The grade measured at the ceremony is not a permanent ceiling. Early Southern Border chapters already name talent-raising Gu as a route that can change aptitude. ^{ch. 46 ch. 91} Fang Yuan lists finding such a Gu as the most direct way to break past a low measured grade. ^{ch. 91}

The primeval sea and primeval essence

Inside the aperture is the primeval sea. The fluid it holds is primeval essence. A Gu Master is someone who has opened the aperture and uses that essence to feed, refine, and manipulate Gu. ^{ch. 7} Essence is spent to activate Gu and recovers on its own over time. Higher talent means a larger store and a faster recovery rate. ^{ch. 22} For a C grade talent like Fang Yuan, natural recovery is about four percent of the aperture’s store per hour, or about twenty-four percent in six hours. ^{ch. 10} An A grade talent like Fang Zheng recovers about eight percent per hour, forty-eight percent in six hours, twice Fang Yuan’s natural rate. ^{ch. 10 ch. 50}

Essence also changes character as its owner advances. Essence at rank one is green copper, at rank two is red iron, and at rank three is white silver. ^{ch. 26} It is yellow gold at rank four. ^{ch. 55} It is purple crystal at rank five, with shade deepening by stage from light purple through violet and deep purple to crystal purple at peak stage. ^{ch. 379} Density rises with rank as well: one portion of red iron equals ten of green copper, and one portion of white silver equals ten of red iron. ^{ch. 26}

Primeval stones

Essence also exists outside a body, as primeval stones. They are the ordinary currency of the mortal Gu world, and the early Southern Border chapters run on earning them and spending them. ^{ch. 8 ch. 107} A later chapter is titled for the claim that primeval stones are material goods. ^{ch. 111}

They are not only coins. Once someone is a Gu Master, they can extract primeval essence from a stone to replenish the primeval sea in the aperture, so stones are both currency and a cultivation supplement. ^{ch. 8}

After the divide