In the reality of Gu Master cultivation, "Humans are the spirit of all living beings, and Gu are the essence of heaven and earth". Gu are living creatures that house fragments of the (Great Dao), and humans cultivate by refining, nurturing, and using these mystical insects to master the laws of nature.
# The Foundation of Cultivation: The Aperture
To begin cultivation, a human must undergo an (Awakening Ceremony), typically at age fifteen, where (Hope Gu) are used to open a (Primeval Sea Aperture). This spherical organ exists in a state of surrealism, housing a Master's (primeval essence), which is the condensation of their vitality, soul, and life potential.
(Talent) is measured by the amount of primeval essence the aperture can hold, divided into four grades:
* Ten Extreme physique: 100% capacity the chance of them growing to immortal is miniscule as they explode before that but when they do they are unmatched in the same rank
* A Grade: 80%–99% capacity; these geniuses can usually reach Rank 5.
* B Grade: 60%–79% capacity; capable of reaching Rank 4.
* C Grade: 40%–59% capacity; typically limited to Rank 2 or 3.
* D Grade: 20%–39% capacity; usually unable to progress beyond Rank 2.
# Ranks and Stages
Cultivation is divided into (nine great ranks). Ranks 1 through 5 are the (mortal realms), while Ranks 6 through 9 are the (immortal realms). Every rank is further subdivided into four small realms: (initial stage, middle stage, upper stage, and peak stage). As a Master progresses, their primeval essence undergoes qualitative changes in color and density:
* **Rank 1: Green Copper.
* **Rank 2: Red Steel.
* **Rank 3: White Silver.
* **Rank 4: Yellow Gold.
* **Rank 5: Purple Crystal.
# The Three Pillars: Refinement, Nurture, and Use
Gu cultivation consists of three fundamental aspects: (Refinement, Nurturing, and Usage).
1. Refinement: This is the process of subduing wild Gu or creating new ones through fusion. It involves using one's will to replace the wild consciousness of the Gu. The first Gu a Master refines is their (Vital Gu), which is inextricably linked to their life; its destruction can cause severe injury or death.
2. Nurturing (Raising): Gu are living beings and require specific food to survive. Higher-ranked Gu have astronomical feeding costs, leading to the common saying: "Raising a Gu is like raising a mistress".
3. Usage: Masters activate Gu by pouring primeval essence into them. While single Gu are powerful, experts create (Killer Moves)—exquisite combinations of multiple Gu worms that produce amplified effects greater than the sum of their parts.
# Attainment and Dao Marks
A Gu Master's strength is not just determined by rank, but by their (Attainment Level) and (Dao Marks). Attainment represents a Master's deep, intuitive understanding of a specific path (e.g., Strength, Wisdom, Refinement), ranging from (Ordinary to Supreme Grandmaster). High attainment levels grant a "refinement path intuition," allowing them to modify recipes and killer moves instinctively. (Dao Marks) are traces of the Great Dao carved onto a Gu Master's body or aperture, amplifying the power of their corresponding path.
# Immortal Ascension
Crossing the threshold from Rank 5 to Rank 6 is the most dangerous trial, known as Immortal Ascension. The Master must:
* Shatter their mortal aperture to create a hole.
* Draw in **Heaven Qi** and **Earth Qi** from the world, balancing them with their own **Human Qi**.
* Survive a **Heavenly Tribulation** and **Earthly Calamity**.
* Successfully place their Vital Gu into the balanced three qi to form an **Immortal Aperture** (Blessed Land for Rank 6-7, Grotto-heaven for Rank 8-9).
Successful ascension grants (Immortal Essence)—a bead of which is equivalent to a massive amount of mortal primeval essence—and transforms the Master into a (Gu Immortal), allowing them to use the uniquely powerful (Immortal Gu).
# The Apex: Rank 9 Venerables
At the summit of the Gu world are the (Rank 9 Venerables), who are the (Supreme Grandmasters) of their respective paths. They are known as (Dao Lords), possessing the ability to refine all the natural dao marks of their path in the world, making them truly invincible in their era. Throughout three million years of history, only (eleven) such individuals have ever existed.