Chapter Text
Kaeya had never intended to leave Mondstadt forever.
The decision had begun as a possibility, transformed into a contingency, and eventually become a certainty through the simple process of having too much time alone with his own thoughts. Every attempt to find another solution had only brought him back to the same conclusion. If the prophecy was correct, remaining in Mondstadt meant gambling with the lives of everyone he cared about. If the prophecy was wrong, then he would be abandoning his home for nothing.
Unfortunately, Kaeya had never been the sort of man willing to wager an entire nation on the chance that he was mistaken.
The irony, he reflected as he stood outside Dawn Winery long after midnight, was that none of this would have been nearly so difficult if he had not fallen in love with Diluc.
Mondstadt had always come first for him.
Not because Diluc loved the city more than he loved Kaeya, but because protecting Mondstadt was woven so deeply into the fabric of who he was that Kaeya could no longer imagine one existing without the other. He knew exactly what would happen if he revealed the prophecy. Diluc would insist they face it together. He would search for alternatives. He would exhaust every resource available to him before accepting the possibility that Kaeya needed to leave.
And if all of those efforts failed?
Kaeya knew the answer to that question too.
Diluc would choose Mondstadt.
The thought hurt far less than it should have.
Perhaps because Kaeya had understood it long before he ever understood himself.
He remained standing beneath the shadow of the winery for several minutes, staring at the familiar windows glowing softly against the darkness. Somewhere inside, Diluc was likely asleep. The image came easily to him. Diluc had always preferred early mornings to late nights whenever circumstances allowed for it, and after centuries together Kaeya knew the rhythms of his mate's life as well as he knew his own.
The realization made his chest ache.
For all the years they had spent together, for all the arguments and reconciliations and quiet evenings shared between them, Kaeya could still trace the shape of his affection back to something painfully simple.
Home.
That was what Diluc had become.
The man waiting unknowingly inside while Kaeya stood outside preparing to walk away from him.
A bitter smile touched his lips.
It was almost impressive how much damage a person could cause while trying to do the right thing.
The letter felt heavier than it should have as he slipped it from his coat. He had rewritten it six times over the past month and hated every version equally. Nothing seemed capable of explaining centuries of love, fear, and desperation in a handful of pages.
In the end he had settled for honesty.
Or at least the version of honesty he believed Diluc could survive.
The prophecy. His decision. And an apology.
The rest remained unwritten.
There was no mention of how often he had nearly abandoned the plan entirely.
No mention of the nights spent lying awake beside Diluc wondering whether selfishness would really be so terrible if it bought them a few more decades together.
And certainly no mention of the fact that he loved him enough to leave.
That particular truth felt too cruel to put into words.
Kaeya quietly slipped the letter beneath the door and immediately regretted it.
His instincts screamed at him to retrieve it.
To walk inside. To wake Diluc and tell him everything.
For one reckless moment he even considered doing exactly that.
He imagined Diluc's expression shifting from confusion to concern as the story unfolded. He imagined the inevitable argument that would follow. Diluc would insist there had to be another way. Kaeya would disagree. Neither of them would sleep for the remainder of the night.
The image was so vivid that it almost convinced him.
Almost.
Then he remembered the prophecy.
Remembered the vision of fire consuming Mondstadt's skyline.
Remembered the names of the people who would die if he was wrong.
And the moment passed.
When Kaeya finally turned away from Dawn Winery, he did not allow himself to look back.
If he did, he wasn't entirely certain he would keep walking.
The journey began before sunrise. And the first few weeks were the hardest.
Not because of the travel itself. Kaeya had spent enough of his life wandering unfamiliar roads that solitude came naturally to him. What he struggled with instead was the absence.
Every habit seemed designed to remind him of what he had left behind.
He caught himself reaching for a second cup whenever he made tea.
Found himself glancing up whenever a door opened.
More than once he started speaking aloud only to remember there was no one there to answer.
The loneliness settled gradually rather than all at once.
A thousand small wounds instead of a single fatal blow.
By the time he realized he was pregnant, he was already too far away to convince himself that returning would solve anything.
The discovery left him sitting motionless for nearly an hour. The healer who delivered the news appeared deeply concerned by his silence.
Kaeya couldn't blame her.
He wasn't entirely sure how to react either.
A child.
His and Diluc's.
The thought should have filled him with joy. Instead it left him staring at the wall while grief quietly hollowed out his chest.
Because suddenly leaving no longer affected only him.
Suddenly there was someone else who would grow up without knowing their father. Someone else who would inherit the consequences of a choice they never had the opportunity to make.
That night Kaeya cried for the first time since leaving Mondstadt.
No one witnessed it.
He was grateful for that.
Even centuries later, it remained one of the loneliest nights of his life.