Yin Mountain

Biodata

Environment

Yin Mountain Realm is a dead, underworld-aligned landscape reached through a node in the Yin Mountain Metro. Its sky is monotonous gray, without sun, moon, or stars; its gray-black earth is formed from lifeless mountain ranges and bare rock, with decay and death saturating the air 4.

• Black stone hills — Barren terrain where fissures periodically release dense yin energy that becomes Mythic Factors 8.
• Yin-energy fissures — Cracks in the land that can emit resources, but also close unnaturally when the realm enters a period of suppression or instability 8 19.
• Blackstone Mountain — A sparsely populated region of the realm with few resources, Yin souls, Ghost Soldiers, or Mythic Walkers 18.
• Underworld affinity — Its ghost- and spirit-related mythic materials can resonate with traits tied to the Netherworld, including White Impermanence’s Wealth-at-First-Sight Hat 15.
• Native threats — Known inhabitants include Vicious Ghosts, Yin Ghosts, Ghost Soldiers, and Yaksha Demons 4 6 8.

Access Through the Yin Mountain Metro

The Yin Mountain Metro emerged in Yin Mountain City two months before Zhou Yao discovered its nature. It grew from two stations to eleven while becoming an ordinary part of civilian life, despite the city lacking the means to construct a subway system 1.

The Metro is a product of a mythic invasion: a temporary overlap between the present world and the Celestial Circuit Realm. Its tunnels contain the same weak Mythic Factors that Zhou Yao absorbs during daily travel 2 4.

• Realm node — Yellow Wind Little Sage reached the realm by traveling deep through a metro tunnel and crossing a luminous fissure beside a vast, bottomless gorge 4.
• Cognitive interference — The Metro alters or erases memories concerning itself. People can forget prior investigations, and passengers expelled from it may lose the memories needed to return 67 84.
• Eighteen Levels of Hell — The Metro is a manifested marker of the Eighteen Levels of Hell and follows the Netherworld’s order 69.
• White Impermanence’s Edict — White Impermanence’s authority can compel the Metro to stop and permit entry, overriding its own attempts to avoid Zhou Yao 69 77.
• Signpost to Hell — After the Yin Mountain Guardian’s fall, Zhou Yao gains a relic capable of summoning the Metro from an erroneous time-space and using it to access the Eighteen Levels of Hell 98 99.

Northern Yin Mountain Temple

Northern Yin Mountain Temple is a divine realm manifestation that appears within Yin Mountain Realm during expansions. It manifests at dusk, remains for three days, and has appeared twelve times according to the Yinshan Investigation Branch 28.

• Its ancient structure is marked by faded murals, cloud-patterned stone railings, and an ebony plaque bearing its name in gold characters 28.
• Entry requires meeting unknown special conditions, which may involve age, virtue, or the absence of evil intentions 28.
• The temple contains the Northern Yin Six Heavens Divine Seat of Mount Luofeng, a false Earthly Deity divine seat linked to Northern Yin Fengdu and the suppression of the Netherworld 34.
• The divine seat’s continued suppression of the Eighteen Levels of Hell disrupted Baron Xothos’s attempt to use the Yinshan Train to establish coordinates to Western Hell 84.
• The Yinshan Investigation Branch demands that anyone discovering a Mountain God Tablet trade it to the Branch at any price 28.

History

Emergence and First Exploration

The Metro’s unexplained arrival concealed Yin Mountain Realm from the public. While ordinary residents accepted the new subway without question, Zhou Yao recognized it as a mythic-invasion phenomenon and gradually harvested weak Mythic Factors from its yin aura 1 2.

After creating Yellow Wind Little Sage, Zhou Yao used the incarnation’s wind arts to infiltrate the Metro tunnels. The avatar passed soul-targeting whispers unharmed because it had no independent soul, then crossed the realm node and encountered a Vicious Ghost shortly after arriving in Yin Mountain Realm 4.

Expansion and Suppression

Yin Mountain Realm began expanding repeatedly approximately two months after the Metro’s appearance, opening regions expected to contain higher-quality mythological materials 21. The Yinshan Investigation Branch concealed the expansion from federal authorities, sealed access to the city, and attempted to monopolize its resources 21.

When Behemoth Technology and three other major corporations learned of the expansion, Xu Yu negotiated exploration rights: each corporation received twenty slots, while Mythic Walkers above Scavenger-rank completion were barred from interfering 21. The Branch later led major exploration teams toward Northern Yin Mountain Temple, fielding an unusually large number of fourth- and fifth-stage Scavengers 28.

Eighteen Levels of Hell Crisis

The realm and Metro became central to a mythological invasion involving the Eighteen Levels of Hell. Baron Xothos attempted to exploit the Yinshan Train to connect with Western Hell, while the Yinshan Investigation Branch later used Yin Mountain City in a Ghost King Gate-Entering Ritual 84 91.

The ritual produced Yin soldiers, mass ghostification, and the threat of sacrificing the city’s population. Zhou Yao and his incarnations disrupted the ritual, freed one hundred thousand spiritual souls, and helped cause the Yin Mountain Guardian’s eventual judgment by the Eighteen Levels of Hell 91 94 98.

Associated Groups and Figures

• Zhou Yao — First identified the Metro as anomalous, entered Yin Mountain Realm through Yellow Wind Little Sage, and later gained the means to summon the Metro at will 1 4 99.
• Yellow Wind Little Sage — Zhou Yao’s first incarnation; explored the realm, gathered materials, and used its wind arts to evade threats within the Metro and realm 4 18 93.
• Yinshan Investigation Branch — Concealed the realm’s expansion, controlled exploration access, and later orchestrated the False God ritual in Yin Mountain City 21 86.
• Xu Yu — Captain of the Investigation Branch’s First Enforcement Team; negotiated with the four corporations and oversaw expeditions to Northern Yin Mountain Temple 21 28.
• Yin Mountain Guardian / Yu Changyong — A Fire-Stealing Rank powerhouse whose attempt at ascension was tied to the Ghost King ritual; he was ultimately judged through the Eighteen Levels of Hell 92 94 98.
• Baron Xothos — Sought to use the Yinshan Train to open a route to Western Hell, but was obstructed by the Northern Yin Mountain Temple’s suppressive authority 84.