During his time in Liyue Harbor, Xiao had taken on the task of guarding its surroundings, but there was not much fighting to be done. So he often visited his elder brother Bosacius. He knew that Bosacius's karmic debt was worsening. Sometimes Bosacius even forgot who Xiao was, treating him like a stranger trespassing on his property, shouting at him and trying to drive him away. Sometimes he forgot himself entirely, his memories slowly slipping away.
So when Xiao learned that Bosacius had gone missing, he was deeply worried. Without Xiao to watch over him, if Bosacius's karmic debt flared up, there would be no hope of recovery. Xiao immediately wanted to go find Bosacius.
But Xiao could not ignore his duty. Before leaving Liyue Harbor to search for Bosacius, he had to resign from his task of guarding the city. Just as he was looking for Rex Lapis, the archon had already gathered the adepti to announce earth-shattering news.
The ancient nation of Khaenri'ah had been destroyed. A calamity of monsters had descended. Endless monsters were emerging from beneath Khaenri'ah, spreading across Teyvat with the ruined nation as their center. Mondstadt, Inazuma, Sumeru, Fontaine, Natlan, Snezhnaya, and Liyue—every nation was a target.
Hearing this, all the adepti were shocked. Like Rex Lapis, they had long considered the possibility of Khaenri'ah's end and had imagined this day might come. But they had never expected it to arrive so suddenly, so quickly, bringing such an unsettling disaster.
In that moment, all the living adepti of Liyue had gathered: Mountain Shaper, Moon Carver, Cloud Retainer, Skybracer... And Xiao, as the only yaksha capable of fighting, was also present.
Unlike the other adepti, Xiao had never concerned himself with the continent's affairs, only with battle. This was his first time hearing the name Khaenri'ah. So when he learned of its destruction, his expression did not change. But seeing the shock on the other adepti's faces, he knew that Liyue was in grave trouble—perhaps even a threat to its very survival.
He wanted to leave to find Bosacius, but he never found the chance to speak. Even when Rex Lapis finally gave his orders, Xiao still had no opportunity.
Looking at the adepti, Rex Lapis's expression was unusually serious. "The monsters of Khaenri'ah will emerge from the sea east of Liyue, splitting into two forces to invade Liyue and Inazuma on the opposite shore. All adepti, follow me out to sea to meet them."
At his command, the adepti's fighting spirit ignited.
Mountain Shaper: "By your command, Rex Lapis."
Moon Carver: "I will follow Rex Lapis's footsteps."
Cloud Retainer: "For Liyue and its people."
Skybracer: "Monsters? Let's crush them."
One by one, the usually aloof adepti burned with battle lust, ready to defend the nation they had built together. Even Rex Lapis himself would lead the charge, underscoring how seriously he took this invasion.
Though Xiao desperately wanted to search for Bosacius, seeing so many adepti following Rex Lapis into battle weighed on his heart. As a yaksha born for combat, how could he shrink from this?
"Rex Lapis, give me my orders," he said.
If Bosacius knew of the monster invasion and encountered them, he too would choose to fight. Protecting Liyue had become more important to the yakshas than their own lives.
Rex Lapis started to speak, then hesitated. He could see what was in Xiao's heart. But Liyue was in peril, and they needed the yaksha's help.
He spoke seriously. "The adepti and I will go deep into the sea to intercept the monsters. But some will inevitably slip through. Those monsters will surely come ashore at Dihua Marsh. Alatus, I order you to guard Dihua Marsh alone and slay every monster that appears. Can you do it?"
Since the founding of Liyue and his ascension to Geo Archon after the Archon War, Rex Lapis had not been this serious in a very long time.
Hearing his command, Xiao's fighting spirit flared. "I can do it. As long as I live, not a single monster will leave Dihua Marsh alive."
After accepting the mission to guard Dihua Marsh, Xiao dared not delay. He set out immediately.
As he left Liyue Harbor, he looked back at the prosperous city and said with determination, "Brother Hepuyuan, Brother Bosacius, don't worry. I will protect this nation. Brother Bosacius, after I've slain the monsters, I will come find you. Wait for me."
His heart was full of conflicting emotions, but his gaze was resolute. He set off alone for Dihua Marsh.
What awaited him there was not the cheers of the people or a thriving land, but tens of thousands of monsters. What awaited him was the hardest, bloodiest battle of his life—one that would nearly kill him.
After Xiao left, Rex Lapis led the adepti out to sea from Liyue Harbor, intercepting the monsters head-on to protect Liyue's homeland.
Not only that, before departing, Rex Lapis made other preparations. To prevent small groups of monsters from invading Liyue's western side, he stationed a large number of Millelith soldiers near the Chasm, ready to defend against any incursions.
At the time, this was a very wise decision. But even though Rex Lapis took the disaster seriously, he still underestimated its scale. Even he could not have imagined that the number of monsters invading Liyue through the Chasm would far exceed all expectations—and the Millelith's ability to resist.
If not for an uninvited, nameless yaksha who sacrificed his life to destroy all the monsters, the people of Liyue would have faced a bloody catastrophe.