December 1st
Teyvat City Expo, Mondstadt City.
The winds of winter blew with a gentle chill through the sprawling avenues of Teyvat City, but it did little to stifle the energy of the crowds pouring into the monumental glass-and-steel halls of the Teyvat International Expo Center.
It was here that the world had gathered for the Teyvat City Expo—a monumental international trade conference centered on urban development, intercontinental cooperation, and the technological revolutions shaping tomorrow's cities. From new maglev transportation grids to next-gen energy infrastructure, the Expo was the pulse of progress.
But this year, there was a geopolitical undercurrent few failed to notice.
Jarilo, the northernmost sovereign nation on the Teyvat continent, had made a rare and official appearance. Its highest-ranking leader—Cocolia Rand, the Eighteenth Supreme Guardian of Belobog—arrived under heavy security and tighter airspace protocols than ever before. Her presence was a signal, both diplomatic and strategic.
Despite being cloaked in perpetual snowfall and isolated behind the frostbitten veil of the Emberhowl Straits, Jarilo remained a mineral powerhouse, rich in strategic resources, a bastion of industrial steel and mining exports. The nation itself was divided into two territories:
Mainland Jarilo – the urban and political heart of the nation, centered around its capital: Belobog, a city of grandeur and cold stoicism.
Boulder Island – an unforgiving outcrop northeast of the mainland. A mining colony that also served as a strategic northern listening post—and the coldest inhabited zone in the entire continent.
Though known for its industrial influence and economic growth, Jarilo's military presence was woefully underdeveloped.
Their army was strong, entrenched in cold-weather tactics and fortress warfare—but the skies told another story.
Just one month prior...
The roar of afterburners had thundered over Marcotte Air Force Base, as Teyvat celebrated one of its proudest moments in aviation history:
The Teyvat International Air Show.
An aerial spectacle commemorating the 15th anniversary of the Teyvat-Snezhnaya War's conclusion.
It was the largest gathering of airpower Teyvat had ever witnessed.
The ramp held a titanic Elephant Walk, lined wingtip to wingtip with modern multirole aircraft and hardened strike jets:
The Teyvat Strategic Strike Group took center stage, with jets from Waltz Squadron and Primordial Squadron gleaming in the sun, their tails adorned with war markings from past campaigns.
A rare reappearance of the Emberhowl Air Command Squadron, with their legendary quartet of black-painted Grumman F-14A Tomcats, still deadly, still majestic.
The Teyvat Golden Angel Demonstration Squadron dazzled with high-G turns and knife-edge passes.
Even civilian aircraft joined the salute—Boeing, Airbus, and Embraer bringing in widebodies, while classics like the DC-3, DC-6, and 707 reminded everyone of aviation's golden age.
But amid all the fanfare... there was silence from the north.
Because Jarilo, despite its wealth and industrial steel, fielded only a single primary air force squadron.
Their air doctrine leaned entirely on the ground—anti-air missile grids, railgun emplacements, armored divisions hardened for snow war. The skies? Barely defended.
Only one fully operational combat unit existed:
The 335th Fighter Squadron, 4th Air Division.
Better known as Silvermane Squadron.
Equipped with a limited fleet of F-15E Strike Eagles, Jarilo's skies rested on the shoulders of barely a handful of airmen.
As of this very moment—only four Strike Eagles were active, flown by elite aces. The rest were mothballed or handed off to under-equipped auxiliary squadrons, flying a patchwork of hand-me-down fighters: F-16C Vipers, F/A-18E Super Hornets, Dassault Rafales, and Eurofighter Typhoons, barely kept in the air by overstretched maintenance crews.
A single successful airstrike on Belobog's airfield would be enough to cripple their national air defense.
Teyvat took notice.
In response to growing instability in the far north, Teyvat's President, Sangonomiya Kokomi, and Supreme Guardian Cocolia met under secure treaty protocols. The result was swift and definitive:
The Teyvat-Jarilo Nation-in-Arms Act
A historic joint-military agreement that would change the fate of both nations.
Under this treaty:
Teyvat's Six Nations—Mondstadt, Liyue, Inazuma, Sumeru, Fontaine, and Natlan—would provide direct military support to Jarilo.
Training operations would begin between the Teyvat Air Defense Force and Jarilo's limited air units.
Teyvat aircraft would be permanently stationed at forward bases inside Jarilo, enhancing their aerial defense capabilities.
And most importantly, if Jarilo came under attack—by any nation or armed group—Teyvat would be authorized to respond with full military power.
The treaty also authorized the deployment of elite units, should conflict ignite.
At the heart of that vanguard would be:
Primordial Squadron, under the command of Jean Gunnhildr, the Iron Valkyrie of Mondstadt.
Waltz Squadron, led by none other than the "Regina of the Skies" herself—Furina de Fontaine, the deadliest ace in Teyvat air history.
And a shadow unit of surgical precision: the Teyvat United Peacekeeping Force's Special Operations Division—Gulliver Squadron, composed entirely of ace pilots from New Eridu, Inazuma, flying highly modified F-15Js.
In the event of an attack...
Section Six of the Act would be activated:
"Any form of hostile incursion against the sovereign territory of the Jarilo Republic—by foreign power or insurgent group—shall trigger immediate deployment of Teyvat's elite air forces: including, but not limited to, the Strategic Strike Group and the Special Operations Unit, until the hostile threat is neutralized and national sovereignty is restored."
The line had been drawn.
The cold north, silent and pristine... was about to burn.
And the skies of Jarilo would soon become a battlefield
From an unknown form.