Archive of Our Own ^beta

Chapter Text

Title: he lived, and he burned

AU: CXS Survived AU

he lived, and he burned

Cheng Xiaoshi died.

Then he didn’t.

The world had moved on. Rubble swallowed the light. The collapse was final, everyone said. A clean ending. A tragic one. But not every story wants to stay buried. Some stories claw their way out through cracks in time.

He woke up hours later in a ruined building under an emergency floodlight, covered in blood, ash, and something less explainable. His body wasn’t broken. But it didn’t feel right. Something had been rewritten. Something inside him hummed — hot, unstable, like fire barely held together by skin.

When he opened his eyes, the light flickered. And didn’t stop. His reflection in a broken shard of glass stared back — unfamiliar. Yellow eyes. Glowing. Not metaphorically. Not a trick of light. Glowing like the truth of time was burning through his skull.

Lu Guang found him two days later, standing on the edge of a rooftop like he was trying to figure out if gravity still applied to him. He didn’t fall. He didn’t blink.

“Xiaoshi?”

Cheng Xiaoshi turned. The glow in his eyes didn’t fade.

“It’s me,” he said. But he didn’t sound sure.

He tried to smile. It came out wrong.

The timeline didn’t kill him. It changed him.

He remembered everything. Every single time he changed a choice that wasn’t his. Every life saved that cost someone else. Every time he said, “I can fix this,” and couldn’t.

And now it was inside him — all of it. Every consequence, every paradox, stitched into the shape of him like thread through paper. The timelines didn’t forget. And neither could he.

People started whispering. About the glowing-eyed figure on rooftops. About how time stuttered around him. About how anyone who tried to mess with fate in that city now… just disappeared.

Lu Guang didn’t believe the rumors.

But when he looked at Cheng Xiaoshi, he didn’t see his best friend anymore. He saw someone who knew too much. Someone who had been too much. Someone who might still be trying to save people — but at what cost?

Qiao Ling asked him, once: “Do you think he’s still in there?”

Lu Guang didn’t answer.

Sometimes Cheng Xiaoshi sits at the top of the old building where it all ended. Where it started. The city lights below flicker like broken data.

He watches. He remembers. He waits.

He doesn’t know what he is now. Not really.

But he survived. And that, somehow, feels more dangerous than dying.

End.

Chapter Text

the favor he shouldn't ask

Lu Guang hadn’t seen him in a month.

Thirty-one days, to be exact. Not that he was counting. (He was.)

He’d convinced himself that maybe Cheng Xiaoshi was... resting. Recovering. Disappearing. Anything but standing outside his window again like nothing had changed.

But now he was here.

The same worn hoodie. The same cocky smile, cracked down the middle. And eyes that still glowed faintly yellow even in the dark, like something radioactive never left his bones.

“Miss me?”

Lu Guang didn’t answer.

He didn’t say how the sight of him hit like a blade. How it felt like looking at a photo of someone you already buried. Someone who came back wrong.

Instead, he stepped aside, letting him in without a word. The air between them snapped tight — like something had been left unfinished the last time they spoke. Because it had.

Cheng Xiaoshi walked in slowly, not looking around, not fidgeting. Just... quiet. Hollow.

“What do you want?” Lu Guang asked finally.

Xiaoshi blinked. “Straight to business. No ‘how have you been’? Not even a coffee offer?”

“You don’t drink coffee. You always said it tasted like regret.”

“Well,” Xiaoshi said, mouth twitching into a bitter half-smile, “maybe that’s fitting now.”

Lu Guang didn’t flinch. But he felt the weight behind those words.

Xiaoshi sat on the windowsill, his usual spot, like muscle memory brought him there.

“I need a favor,” he said at last.

Lu Guang’s heart dropped before he could stop it. “You’re not supposed to have powers anymore.”

“Exactly.” He looked up, eyes glowing faintly, hands folded in his lap like he was keeping them from shaking. “That’s why I need yours.”

Silence. Then:

“You want me to send you back in time?” Lu Guang’s voice was calm. Too calm. “Using the ability I got after... after you—”

“Died. Yeah.”

Lu Guang’s jaw clenched. “Why?”

Cheng Xiaoshi looked at him. And in that moment, he looked more like himself than he had in months. Tired. Stubborn. Too full of guilt for one body to carry.

“Because there’s something I have to do. Something I have to change.”

“Change what?”

Xiaoshi didn’t answer.

Lu Guang stepped forward. “No. If I’m doing this, I need to know—”

“Lu Guang,” he said, softly. “Please.”

That single word — please — cracked everything open.

They didn’t speak as they prepared. A photo from Lu Guang’s past. The same steps they used to follow together, back when this was routine. Back when it didn’t hurt so much to try and fix things.

Lu Guang hesitated with the photo in hand. “If you go back, and you change something... I won’t remember it. Not unless it ripples far enough. Not unless you make it personal.”

Xiaoshi gave a tiny smile. “It’s always personal, isn’t it?”

And with that — hand pressed to the photo, breath held — he slipped into the past.

It was only minutes. But for Lu Guang, it felt longer. Something in the air buzzed like electricity waiting to bite.

When Cheng Xiaoshi came back, he was... still. Too still.

“What did you do?” Lu Guang asked, stepping toward him.

Xiaoshi’s eyes flickered with something unreadable. “You’ll know when the time’s right.”

“That’s not good enough.”

He looked down. “You didn’t tell me when you broke the rules first.”

Lu Guang froze. “That’s different.”

“Is it?” Xiaoshi’s voice was sharp now. “We agreed — no interfering with each other’s lives. No fixing. No redoing. You broke it first.”

“I saved you.”

“So did I,” Cheng Xiaoshi whispered. “You just don’t know it yet.”

Lu Guang stared at him. “Why can’t you just tell me?”

Xiaoshi looked at him for a long moment. “Because if I do... you’ll try to stop me. Or worse — you’ll try to go back and undo it.”

“I have the right to know.”

“Maybe. But not yet.”

And then it happened — that flicker. That blink. A shift in light, like the world exhaled around them.

Lu Guang reached out instinctively. “Wait— Xiaoshi—”

But Cheng Xiaoshi was already gone.

No light. No sound. Just the echo of what he left behind.

A photo on the floor. Burned around the edges. And silence.

Lu Guang sat down slowly. He didn’t know what Xiaoshi had changed. Or why.

But something in the room felt different. Familiar in a way he couldn’t place. Like an old scar he’d forgotten, aching again without warning.

Whatever Cheng Xiaoshi did... it mattered. It always did.

And he was afraid to find out how much.

End of Part 2.

Author’s Sneaky Note:
surpriseee ~ 😈 you thought it ended there?? nooope. LG POV just dropped like a memory you weren’t ready for. it’s not over yet, and neither is what CXS started enjoy this small pov of Lg Xoxo

There was a space where Cheng Xiaoshi had been. It followed Lu Guang around like a shadow.

He knew better than to expect answers. Xiaoshi never gave answers. He gave puzzles. He gave rules, then broke them. He gave everything, then left.

And now Lu Guang was left with questions in yellow light, with timeline scars stitched into memories that didn’t fit quite right anymore.

A new photo in his inbox. Timestamped a day before they ever met.

Lu Guang closed his eyes.

"You idiot," he whispered. "What did you save me from?"
To be continued in Part 3...(yes actually this time)

Chapter Text

He doesn’t remember falling asleep.

Just the hum of the fan overhead. The distant city traffic. The quiet click of the power strip switching off. Then — nothing.

And then — this.

He’s standing in the middle of a basketball court. Chain-link fences. Sunlight soaked into the ground so deep it smells warm, like it never left.

It’s familiar. Too familiar. Like something he tucked away long ago.

A ball bounces twice and rolls toward him. He bends to pick it up, muscle memory stronger than thought. It’s still spinning in his hand when someone jogs into view — dark shirt, lopsided grin.

Cheng Xiaoshi.

Lu Guang doesn’t breathe. For a second, he can’t.

CXS slows, eyes sweeping the court. They land on Lu Guang, the way they always did. Like he’s surprised to see him, like he’s already amused.

“Hey,” LG says, holding the ball out. “Yours?”

This should be the part where he smiles. Takes it. Asks him to play. Asks him his name. Asks him if he wants to be friends.

But he doesn’t.

CXS looks at him — really looks — and then just… walks away.

No smile. No nod. No moment.

He turns his back, jogs back to his group, and the sound of sneakers on concrete swallows the silence left behind.

Lu Guang stands there with the ball still in his hands. He can feel the seams pressing into his fingers, feel the heat radiating off it, feel his throat start to close around something unsaid.

“Wait,” he tries. “Aren’t we—”

But the words fade, thin and useless. He doesn’t know what he’s trying to say anymore.

Because this isn’t how it happened. This isn’t how it was supposed to happen.

He takes a step forward. And the court ripples.

The colors shift — not fully, just slightly out of sync. Like the sun is flickering behind a different sky. Shadows start crawling too slow. The chain-link fence hums with radio static.

“You never met him here,” says a voice — not CXS, not Him, just something inside the dream. “This is the one where you missed him.”

Lu Guang turns. The voice is gone. The court is empty.

The ball drops from his hands and rolls out of frame.

Next frame.

He’s in the studio. It’s clean. Too clean. Like it was never lived in.

No polaroids on the wall. No rice bowls in the sink. No Cheng Xiaoshi draped across the couch like a cat in a sunbeam.

Lu Guang opens the closet. All the jackets are grey.

On the light table, there’s a photo. He doesn’t remember taking it. In it, he’s alone. Standing in front of the courthouse, arms folded, unsmiling.

He picks up the photo. There’s something written on the back.

“Don’t fix what never broke.”

Next frame.

A staircase. A train tunnel. The sound of voices echoing — but none of them say his name.

He walks into the light. It hurts. He stumbles back. Something cold grips his wrist and pulls.

He gasps. He’s not alone.

Cheng Xiaoshi is standing in front of him, eyes glowing yellow. Not furious. Not even unkind. Just distant. Dimmer than usual. Like he’s somewhere else entirely.

“You don’t remember this one,” CXS says. “That’s okay. I do.”

Lu Guang opens his mouth, but there’s no sound. He wants to ask: Why did you change it?

But instead, CXS leans in. Closer. Closer.

He whispers: “You weren’t supposed to be there. You changed me.”

Lu Guang wakes up gasping. The fan overhead is still spinning. The room is still dark.

He touches his face. It's dry. But his eyes sting anyway.

He glances to the side of the bed. The light table is on.

There’s a single polaroid sitting there, face-down. He didn’t put it there.

He turns it over.

It’s the basketball court.

CXS is walking away.

Lu Guang is holding the ball, mid-step, frozen in motion.

Written in tiny script at the bottom:

“You made the first move. I made the last.”

He doesn’t sleep again that night.