Chapter Text
"This is your chance. You are our last hope."
To take another’s life is a profoundly intimate experience.
Whether by mercy or necessity, by love or by deepest animosity, the glide of steel into the base of the skull, severing the spirit irreversibly from its capacity to feel pain, carries with it a silent and soul-rending closeness. Permanence. The burden of time stolen from another, that aches the shoulders, warps the spine, and crushes the chest.
In Khaenri’ah, in the godless lands, when a child dies, the spirit does not linger.
Kaeya turns the blade over in his hands.
His...brother. Of four months.
This boy, lying asleep beneath soft silken sheets, made so full in his comfort that he dozes still, as a sinner and intruder contemplates a weapon over his sprawled form. This boy, who earned the love of his Archon just a few scant weeks ago, at the tender age of ten.
In Mond, if this boy dies, Barbatos would sweep the spirit to safety in Celestia.
Or so the stories go.
Kaeya runs a thumb against the flat of his blade. Something presses his body into a hunch, where the carefully distributed pressure of his gangly limbs against the mattress shifts forward, so that he leans over the boy, cutting into the pale sheet of moonlight that blankets his target. He can almost feel the warmth leaking through the covers. Each soft breath echoes in the silence. Striking distance.
He wonders idly if a spirit that lingers in Celestia would weigh more, or less, than the dusted voices of Khaenri’ah.
To take another’s life is a profoundly intimate experience.
Tonight, it would be neither a mercy nor a necessity.
As shattering as the truth about Teyvat would be to this boy’s world, as tightly as it had bitten into the throats of grown men, leaving behind nothing but bony blue corpses and rope burn, the true mercy would simply be to grant him ignorance. And in this family, despite the lectures, despite the lashing words and blunt beatings,
Kaeya is safe without having to kill.
It does not ring even remotely rational. He is Khaenri’ahn in a foreign house; severing this boy’s spine is as good as severing his own.
The blade glints.
Metal reflects the light of the full moon, prying his attention from steel and skin.
The moon.
Mond.
This boy.
Khaenri’ah has etched a decade’s mark into Kaeya’s body. His heart, his eyes, his skin, his very blood: tributes to the duty he owes to both his home and the whole of Teyvat, unwitting as its inhabitants may be. In the face of that unfathomable fate, in the face of so small a space between his neck and the blood-debt chains of his loyalty to a suffering homeland, a father and a brother trying their damndest to worm through…
Such simple affections brush cloyingly against the jugular. Such warmth distracts from the good he is slated to pay not just this boy, but every Khaenri’ahn, and every unknowing denizen of this land cursed with gods—
Something wets his hand.
To take this boy’s life would be to simultaneously break the binds of his righteous duty, and the emergent ties of this new, soft, wholly foreign loyalty, in one swift thrust of steel into flesh. To take this boy’s life is as good as severing his own wretched, hunched spine.
And to sever the spirit by the spine is to remove it irreversibly from the capacity to feel pain.
The moon glints once again in the metal.
Another drop of something wet, this time on the flat of the blade, and Kaeya raises a hand to his face to follow the chilling trail of tears down his own skin. His fingers stutter against the curve of his cheek.
Shaking.
It must be from the cold.
He lowers the blade, peers out the window. Unconsciously, his eye jumps to search for Khaenri’ah, but the soft light of the full moon is a reasonable comfort for when he fails to find what isn’t there.
He sheathes his blade.
He drops it on the ground.
He kicks it under the bed.
Shivering violently, he scrambles to throw on the voice of a scared child as he takes his brother’s shoulder and jostles him awake.
“Diluc! Diluc!”
“Mnngph… Hnnn? Kaeya…?”
“Diluc…!”
“What’re...what're you doing…? Are you...crying?”
The small sob is unscripted. The heat behind his eyes is untamed. Kaeya’s voice cracks as he clamps onto his brother’s arms and says, helplessly, “Nightmare.”
The best lies are part truth. How else to describe the warring binds of righteous responsibility and fledgling familial affections, tightening around his scuffed throat? He catches a glance of his younger brother’s concerned eyes.
His duty is non-negotiable. It is etched into his very identity, irremovable as his own skin and blood, this debt to both Khaenri’ah and Teyvat at large, and he accepts it with grace.
But this other thing?
Airy, pale, and delicate as the light of the full moon streaming in through the window as Diluc peels back the sheets to welcome him in?
This is a choice.
And Kaeya thaws into an embrace warmer and stronger than any chain.
(Neither of them hear the click of the door sliding shut in the night, or the tap of the Master’s shoes down the hall.)