Yin Mountain

Biodata

Feature	Details
Name	Yin Mountain
Original Name	阴山
Alias(es)	Yin Mountain Realm
Type	Celestial Circuit Realm corresponding to Yin Mountain City 4
Status	Previously subject to recurring expansion; its associated Mythic Invasion was suppressed, followed by an Arctic Exorcism Institute investigation 21 28 83 100 106
First Appearance	Chapter 4 — “Yin Mountain Realm” 4

Environment

Yin Mountain Realm is a dead, underworld-aligned landscape reached through a node in the Yin Mountain Metro. Its sky is ordinarily 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. During a declared Realm Restart, a massive crimson sun appears above Blackstone Mountain, breaking the usual featureless sky while the land below falls into unnatural stillness 18 19.

• 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.
• Withered Wood Haunted Forest — A deathly forest associated with another Mythic Invasion Node. An enormous withered banyan tree bears human-shaped wooden burls, and a crack in its trunk connects the forest to Yin Mountain Realm. Yu Changyong later searches this region for Yellow Wind Little Sage 20 84.
• Black Mountain — The site of the Black Mountain Old Demon’s revival and the battle involving the Yin Mountain Guardian, Black Mountain Old Demon, and Tree Demon Granny 92 97 98.
• 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.
• Yinshan Cold Iron — A material used to forge the Ghost Soldier’s Steel Trident, an Underworld Artifact tempered with a century of ghostly qi 18.

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. Zhou Yao later deduces that each newly added station corresponds to an expansion of Yin Mountain Realm 22.

• 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.
• Ghost passengers — The last train observed during Yellow Wind Little Sage’s first infiltration carried pale figures wearing hospital gowns and red burial clothes. Deeper in the tunnel, overlapping whispers attacked the soul 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.
• Blood Pool Station — A new station formed when the Metro’s expansion connected to the present world 84.
• Central Throne — After gaining control of the Eighteen Levels of Hell’s core, Zhou Yao can use the Central Throne to command their laws against Fire-Stealing Rank opponents. The train’s temporary manifestation in the present world nevertheless has limited power and is insufficient to suppress a fully advanced False God 83 87.
• 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, including outside Yin Mountain City 98 99.
• Internalized summoning — Zhou Yao subsequently absorbs the Signpost to Hell while condensing the Palace of the Tai Sha Liangshi Sect, allowing him to summon the Metro without relying on the external relic 109 110.
• Divine Status support — Following that advancement, Zhou Yao can maintain Divine Status within the driver’s cabin or the Metro’s sphere of influence without relying entirely on the Central Throne 110.
• Private refuge — Zhou Yao hides the Metro beneath his residential complex during the post-crisis investigation and later stores sensitive treasures inside it as a secure private space 106 111.

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 temple’s divine seat anchored the Yinshan Train’s direction and obstructed Baron Xothos’s attempt to establish coordinates to Western Hell. Its suppressive influence eventually dissipated, but Zhou Yao then disrupted the Baron’s sacrifice 79 84.
• The Yinshan Investigation Branch demands that anyone discovering a Mountain God Tablet trade it to the Branch at any price 28.
• Fu Ming and Hui Yuan, ghost-gods associated with the temple, explain its origins and rules to Yellow Wind Little Sage. The temple’s ordinary Mythic Materials had already been removed by the Investigation Branch, while the Godhood of Mount Luofeng remained protected by a rule allowing only someone from the Netherworld to touch it 34.
• The Investigation Branch conducts lethal experiments on ordinary people to test the temple’s entry conditions. The fifth-rank Scavenger Flesh Mountain oversees the experiments and attributes changes in the rules to a Fire Stealer’s interference 46.
• Yellow Wind Little Sage ultimately swallows the incomplete Godhood of Mount Luofeng while at Scavenger Second Rank, making a dangerous leap that breaks through his fate’s limits. Zhou Yao later refines that divine position through the Eighteen Levels of Hell and his vow to restore Netherworld order, transforming it into the Immortals’ Cast-Off Husk-quality Six Heavens of Mount Luofeng Mythic Trait 185 190.
• Yellow Wind Little Sage’s approach to the temple also triggers a remnant image reenacting the Yellow Wind Monster’s use of Samadhi Divine Wind to sweep through the Underworld 204.

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 had begun expanding repeatedly just over two months before Xu Yu’s confrontation with Behemoth Technology’s Rock Giant, 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. The Branch used declarations of a Realm Restart as a pretext to seal the realm; one such declaration accompanied a crimson light and ordered all Mythic Walkers to leave within half an hour 18 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.

The continuing expansions and increasingly frequent platforms were ultimately revealed to be Baron Xothos’s handiwork, part of his effort to redirect the Yinshan Train toward Western Hell 79. Zhou Yao had earlier connected each new Metro station to a corresponding realm expansion and recognized that the Branch and corporations’ information blockade prevented residents from learning of the danger or freely leaving the city 22.

After Yellow Wind Little Sage stole the Mountain God’s Godhood and Skysweeping Arrow, Yu Changyong searched the Withered Wood Haunted Forest for him. Xu Yu was sent into Yin Mountain’s depths to atone for losing the arrow and allowing the thief to escape, while He Yu assumed responsibility for affairs within the realm 84.

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.

Although Zhou Yao’s control of the Eighteen Levels of Hell’s core had already stopped the original Mythic Invasion, the Investigation Branch remained a separate threat, with nearly ten Scavenger Perfection experts and two Fire-Stealing Rank powerhouses 83. The Guardian’s intended False God advancement made delay especially dangerous, since the Metro’s present-world manifestation could not suppress an opponent of that rank 87.

The Unofficial History Club intervened by weaving the Black Mountain Old Demon’s revival and altering the causality surrounding him. Zhou Yao then compiled a version of A Chinese Ghost Story that brought Tree Demon Granny into the conflict 92 93 96 97. Their battle on Black Mountain did not directly defeat the Guardian; instead, their final attack wounded him and forced him into a Mythic Invasion Node connected to Tree Demon Granny’s true body. Zhou Yao’s control of the Metro allowed him to route the Guardian into the Eighteen Levels of Hell for judgment 98.

Investigation and Aftermath

The Arctic Exorcism Institute arrived after the crisis to investigate the Yinshan Investigation Branch and the disaster. While judges handled affairs at the Branch headquarters, Lord Xu took his personal guard into Yin Mountain Realm 100.

For the following two months, Zhou Yao avoided conspicuous advancement under the Institute’s watchful eye. He concealed the Metro beneath his residential complex and kept Yellow Wind Little Sage and Sun-Shooting Little Sage in its driver’s cabin to prevent their discovery 106.

Xie An later reported that he had escaped the blockade by secretly entering Yin Mountain Realm and attempting to cross a realm passage. Spatial turbulence diverted him to the Ganyang Realm, from which he eventually escaped. By the time he learned what had happened in Yin Mountain City, the calamity had ended and ordinary life had resumed, although the Yinshan Black Market had been destroyed 153.

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. The Godhood obtained from Northern Yin Mountain Temple became the foundation of his Six Heavens of Mount Luofeng Mythic Trait 190.
• 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. Yu Changyong later sent him into Yin Mountain’s depths as punishment 84.
• He Yu — Captain of the Branch’s Second Law Enforcement Team; became responsible for affairs within Yin Mountain Realm after Xu Yu’s punishment 84.
• Yin Mountain Guardian / Yin Mountain Warden — 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.
• Yu Changyong — The Investigation Branch’s deputy director and a separate Fire-Stealing Rank powerhouse associated with the Lord of the Land path. He pursued Yellow Wind Little Sage to recover the Mountain God’s Godhood and Skysweeping Arrow 84 92 93 109.
• 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. He was responsible for the realm’s repeated expansions and increasingly frequent platforms 79.
• Four Great Megacorporations — Behemoth Technology, Cloud Palace Group, the Galan Society, and the Hundred Ghosts Consortium negotiated access to newly expanded regions while accepting restrictions on higher-ranked intervention 21.
• Xie An — Came to Yin Mountain following a Seer’s guidance, initially mistaking Yin Mountain City for the intended destination rather than the realm and its Netherworld materials 15. The Seer was later identified as Chu Yuliang, whose divination linked Xie An’s unresolved karma to Yin Mountain City 153.
• Fu Ming and Hui Yuan — Ghost-gods who explained Northern Yin Mountain Temple’s rules and guarded access to the Godhood of Mount Luofeng 34.
• Unofficial History Club — Its members altered causality within the realm to revive Black Mountain Old Demon and facilitate the Guardian’s defeat 92 93 96 98.
• Arctic Exorcism Institute — Investigated the disaster and the Branch’s affairs after the crisis, maintaining scrutiny that prompted Zhou Yao to conceal his incarnations and postpone further advancement 100 106.

---