Soldier On

SUMMARY

Childe is given a mission by the Tsaritsa to stop the Abyss Order’s leader down in the Far South. There, he meets a familiar face, and his duty as Fatui Harbinger becomes a heavy burden he must carry.

An AU where Princess Lumine of the Abyss Order and master swordswoman Skirk are one and the same.

See the end of the work for more notes.

Childe could hardly believe it, but his sight did not betray him. Before him laid his master, whose real name was apparently Lumine, beaten with his own hands, for the first time in his life.

This woman was Skirk, his mentor in the Abyss, and she was also Aether’s long lost sister, Lumine. Childe didn’t fully understand how it all came to be, even when the truth had haphazardly unraveled itself before him. So many questions remained unanswered, like how she hadn’t aged a day since he’d left her a decade ago, still looking as radiant and youthful as ever, still wearing the same cold, determined expression she’d always worn when they trained themselves to the bone.

When she had challenged him to a battle, the battle that would dictate their own course of action from here on out, Childe all too eagerly accepted. It was a perk of being a Harbinger that he had always enjoyed, and finally facing his mentor after ten years, it gave him a rush that not even a battle with Aether could so easily quell.

It was not an easy fight, he admitted. Having to resort to the Foul Legacy running in his blood to defeat her almost left him drained, with only a little energy left for him to still be standing tall. All those weekly sparring matches with Aether paid off; it helped him utilize his Abyssal powers better and more efficiently. He decided he would not thank the Traveler for that later; the idea of using their training to defeat his sister seemed like a terrible thing to tell him.

Looking down at her, Childe couldn’t help but feel a slight swell of pride in his chest from the sight of his mentor beaten down on the ground. She had always given him a difficult time when they’d met in the Abyss, and in between training and their sparring matches, he had never once won. Yet, with the one victory the world had allowed him, a melancholic feeling rose in him like a tidal wave, drowning what was left of the joy from his triumph.

Lumine coughed, blood slowly dribbling from the corner of her mouth. “Claim your victory, my student. If you spare me, then all that I have taught you would have been for naught. If you truly believe in the Tsaritsa and her cause, you will not hesitate. So strike me down, Ajax.”

The sound of his real name in her voice made his chest ache. How he would have loved to be simply Ajax again, just another day of grueling training with his master Skirk, but he couldn’t afford to be so disconnected with reality.

Still, he refused to acknowledge what his master had said. Kill? He lived for the thrill of the battle, but he had always spared his targets, for the mere idea of his Foul Legacy coming back to haunt them was already enough to intimidate them into submission. Taking another’s life was a different subject altogether, one he tried not to cross too often, but not one he wasn’t completely unfamiliar with.

“You do not have to die just so the Tsaritsa could accomplish her ambition. Please, master, if you would just do as I say—” Childe hated the way his voice felt desperate and pleading and pathetic, like he was innocent Ajax again, and not the formidable Eleventh Harbinger, and he was briefly grateful for Lumine interrupting him.

“My student, you have learned nothing.” Childe shuddered at her voice; it was the same firm tone she had used to lecture him for something as simple as holding his bow at the wrong angle. “Just as your beloved Archon made an enemy of the world to fulfill her ambition, I have done and will continue to do the same. Not even my own brother can stop me. Do you understand?”

Childe held his family dearest, and the thought of betraying and killing them for the sake of the Tsaritsa’s cause sickened him. If it came to that—and gods, he hoped not, but if it did—he would rather commit treason than fulfill his duties. The lengths his mentor would go to achieve her own ambition, casting aside what little was left of her family... In another world, perhaps Lumine and the Tsaritsa would make great allies, or friends, even, and he would not have to worry about choosing one over the other. But this was a cruel and unforgiving world, one that did not allow such silly, wishful thinking.

Even as she laid down before him, bruised and battered, Lumine was far stronger and more formidable than Childe could ever hope to be, only if for the fact that she was prepared to lose everything.

And that was precisely why he would have to kill her.

He loved her, truly, but his duties as Fatui Harbinger was what kept his family safe, as the Tsaritsa had duly promised when he joined their ranks. Anything, or anyone, that threatened the Tsaritsa, and by extension, his family’s safety, must be eliminated. In moments like these, his duty would become a burden too heavy to bear, but it was one he must carry out. To falter was to fail. He was still a soldier, after all.

“I understand,” he finally answered, swallowing the dryness in his throat.

Childe drew his bow and aimed for the shot, trying to calm the way his calloused fingers trembled holding the string. It seemed as if the world was keen on playing cruel jokes on him, for the bow he had always struggled with would be the same weapon he would now use to take his beloved mentor’s life. A younger, naïve Childe would have scoffed at the idea.

“There is no room for mistakes in the battlefield,” she used to tell him whenever his hands would hesitate to deliver the final blow. Even now, he could hear her commanding voice in his head as clear as day.

Childe took a deep breath and adjusted his aim.

“There is no room for mistakes in the battlefield,” he muttered, repeating the words quietly like a frantic prayer, as if it offered him the salvation he knew he could never receive. As if echoing his master’s words would make the burden of killing her a little lighter. If anything, it only left a bitter taste in his mouth, one he could never wash off.

In the darkness of the Abyss, her fallen figure glowed like the luminescent spine of a firefly. A light he must snuff out.

Lumine’s expression was filled with pity for him, and it made him want to avoid her gaze, much to his chagrin. Steeling himself, he decided to look her straight in the eyes, those golden, piercing eyes that had always secretly terrified him.

(Truthfully, hers were the only pair that could strike fear in his heart. She had always used it to her advantage, but in hindsight, he didn’t seem to mind, not at all. Not even now.)

Childe took one last glimpse into the face of whom he owed his life to. Even if he could not repay her for saving his neck in the Abyss and bestowing upon him the combat knowledge that he would then use all his life, he could at least give her the gift of dignity in death. Gods know she deserved tenfold more than what he could give.

“I’m sorry, master,” he said, his voice almost faltering.

Lumine smiled softly. “Do not be sorry. I am proud of you, Ajax.”

The arrow pierced her right between the eyes.

NOTES

Title inspired by The Temper Trap's song of the same title, which I recommend you give a listen. This fic's premise is also inspired by this particular scene in Fire Emblem: Three Houses, abrupt ending and all, but with the roles reversed: (spoiler warning) https://www.youtube.com/watch?v=wvHToVO02EU

I wanted to make this fic much longer, with a little more worldbuilding and plot, but halfway through I realized there was no realistic way Childe could beat Lumine in her full power, so uh, here we are, ignoring all of that in favor of some lovely angst.

Still, I'm satisfied with what I've written. Maybe I'll write a similar fic with Lumine killing Childe instead, but that's a hard maybe.

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