Fate's Slave - Shadow Slave X Honkai Star Rail

Snow and shattered stone burst beneath Sunny’s feet as he ran across a battlefield that no longer resembled anything natural.

Every step carried him over fractured ridges, broken ice, and collapsing earth, while the frozen world around him continued to die in slow, violent pieces. Mountains had become ruins. Valleys were split by trenches so deep they vanished into darkness. Snowstorms mixed with dust and debris, turning the air into a blinding haze of white and gray. Behind him, Cocolia pursued without pause, her presence cutting through the chaos like a blade drawn across silk.

Sunny kept his breathing steady only because he forced it to remain that way. His Essence reserves were running dangerously low, and no amount of focus could change that reality. The heat he had endured from his own attack, sustained only through Silent Mist’s enchantments, had consumed far more than he wanted to admit. Without that black haze constantly absorbing and dispersing the inferno he had created, he would have crippled himself long before Cocolia had the chance to finish the job. Even now, both of his hands were burned badly enough that every flex of his fingers sent sharp pulses of pain through his palms and wrists.

It could have been worse, and that fact was the only reason he allowed himself to keep moving without bitterness. His skin was blistered and torn, but his hands still obeyed him. His nerves still functioned. His shadow remained intact, strained but unbroken. Compared to what should have happened when forcing that much flame and Destruction through his own body, he had escaped with far less than he deserved.

Fortunately, Serpent had not stopped working.

The black coils of the tattoo wrapped around his body pulsed faintly beneath his clothes, accelerating the circulation of Essence through his body with all its might. It was not restoring what he had lost, but it was forcing efficiency where exhaustion threatened collapse.

For one final Shadow Step.

That was all he needed.

One clean use. One perfect opening. One moment where Cocolia fell for his trap.

Then everything would end.

Until that moment arrived, surviving mattered more.

A surge of killing intent flared behind him.

Sunny twisted without hesitation. Hail Sorrow appeared in his hand in a burst of white sparks, the black blade manifesting just as the golden chains lashed around it. Destruction surged across the weapon’s surface, golden cracks spreading over dark steel as Cocolia’s spear descended with enough force to split the mountain beneath them.

The impact was monstrous.

Steel met frozen annihilation, and the force behind it shook straight through his body. Sunny felt it first in his wrists, then in his elbows and shoulders, before the shock traveled down his spine like a hammer striking bone. His muscles screamed in protest. His skeleton vibrated under the violence of the collision. It felt less like blocking a weapon and more like trying to stop a collapsing building with one arm.

He did not try to resist it fully.

That would have been idiotic.

Instead, he let the force carry him.

The strike blasted him backward, boots leaving the ground as he was thrown across the snow. He twisted midair, hit the earth shoulder-first, rolled once, twice, and converted the momentum into movement. By the time he rose, he was already sprinting again.

Cocolia was still behind him.

Another spear tore past his head, missing by inches before impaling the frozen ground ahead and exploding the snow upward in a violent spray. Sunny veered left, ducked under the second strike, and narrowly avoided having his ribs shattered by a spinning kick that followed immediately after. Somewhere along the line, she had abandoned the concept of restraint entirely.

There was something deeply offensive about watching a woman made of demonic ice move with the flexibility of an assassin and the force of a siege weapon. Some of her kicks hit like a mother beating her child, ironically enough.

Honestly, it felt personal.

Sunny parried another strike, chains shrieking as they redirected force, and slipped past a vicious downward slash that would have split him from shoulder to hip, hissing in annoyance.

"What... the hell is your workout routine?!"

Cocolia, unsurprisingly, did not answer.

Mostly because she was trying to murder him.

’Fair enough.’

He was going to kill her first, anyways.

The battlefield continued collapsing around them. Vast cracks split the frozen earth without warning, jagged trenches opening beneath their feet as distant clashes between far greater beings distorted the land itself. Entire ridges rose and fell like unstable waves. Snow exploded upward in massive sheets. The sky above felt wrong, fractured in ways that had nothing to do with weather.

Then one crack came too close.

The ground split directly beneath them.

Frozen earth ruptured with violent force, a canyon opening in an instant as snow, stone, and ice were thrown into the air. Sunny leapt, crossing the gap, while Cocolia simply planted one clawed foot against the collapsing wall and continued moving like gravity was a suggestion she found mildly insulting.

As he landed, his mind finally caught up with the obvious question.

’What the hell is happening?!’

This level of Destruction was no longer just collateral from their fight. It was too widespread, too violent, too unstable. Something else was tearing this world apart.

Had the Great Nightmare Creatures come out?

That possibility alone made everything else feel almost manageable.

Without slowing, Sunny extended his shadow sense. Shadows spread through his awareness, slipping across broken terrain and shattered ridges, reaching beyond the immediate battlefield in search of movement, life, and threat.

Then he found it.

Or rather, he found what he couldn’t find.

There was an entire area his senses simply refused to penetrate. A blind spot. A void. It was not emptiness, but absence, like the shadows themselves were being devoured before they could report back. A vast region was covered in something deeper than ordinary darkness.

True Darkness.

Sunny’s expression flattened.

Yes. The Great Ones had arrived.

Fortunately, there did not seem to be many of them, considering there wasn’t a horde rampaging around, as far as he could tell.

Unfortunately, one of them was using True Darkness, which meant it was at least a Great Devil. Worse, it was close. Even worse, it was locked in combat with something strong enough to cause this level of environmental collapse, and wasn’t even done yet!

And the actual problem was that it was near where he needed to go.

If where he stood was covered in True Darkness, or if everywhere except for where he stood was, Shadow Step would not work.

And if Shadow Step failed, then his plan for killing Cocolia without dying alongside her became significantly less elegant.

By which he meant impossible.

’Fucking wonderful.’

It seemed Gloomy’s personality was really showing its effects.

He parried another strike. Then another.

Cocolia’s spear came from above, then from the side, followed by claws, a knee strike, and another sweeping kick that nearly caught him in the spine. Sunny moved like a cornered shadow, weaving and redirecting rather than contesting force directly.

All the while, the world continued to collapse around them.

Snow and earth shattered beneath the aftershocks of distant battles. Mountains groaned like wounded beasts. The air itself felt unstable, as though reality had decided it no longer respected architecture.

Still, Cocolia chased him.

Even when they reached the mountain wall and began sprinting upward across its near-vertical surface, she followed without hesitation. Their feet struck stone instead of snow now, climbing with speed that would have looked impossible to anyone weaker.

Sunny ran first.

Cocolia followed like winter given hunger.

Eventually, they reached the summit.

It was a wartorn platform carved into the mountain itself, broad and ancient, marked by violence far older than the current battle. Snow was thinner here, unable to fully reclaim the scarred stone beneath. Massive slabs of ancient construction lay exposed beneath centuries of frost, their purpose obvious even through ruin.

At the center was a colossal crater.

And behind Sunny stood the corpse of a dead god.

The Engine of Creation loomed over the summit, half-buried and broken, its giant frame twisted by ancient violence. Its head had been blown apart, distorted as though space itself had folded around the wound. Even ruined, it radiated impossible scale. Its presence made mountains feel like background scenery.

Sunny slowed.

Then stopped.

He turned to face Cocolia with a grin that carried absolutely nothing kind.

"Recognize this hunk of junk?"

She advanced.

There was no answer, but none was necessary.

Decay’s Oath around his neck stopped glowing.

The golden light faded.

The shackles vanished first. Then the chains. Then the knuckledusters. Hail Sorrow dissolved into sparks and returned to his Soul Sea.

The golden glow in Sunny’s eyes receded, darkness returning for the briefest moment before amber light replaced it.

Like fire seen through stone. Like a light that refused to go out even when buried beneath endless shadow.

An amber lance appeared in his hand.

At the same time, the Marble Shell forced itself into existence. The Silent Mist vanished, and the onyx stone armor of Preservation emerged in its place. It did not feel like summoning armor. It felt like remembering something that had always been there.

Sunny’s expression shifted.

His thoughts felt distant, as though part of himself had stepped aside to make room for something older and quieter.

And in that strange stillness, he heard himself speak.

"Set the skies ablaze..."

The words left his mouth like an echo.

Then everything changed.

When he had fought Phantylia, the transformation had been partial. A carapace of shadows had formed, streaked with amber light across his right arm. A single draconic wing had erupted from his back with strange thrusters burning force into existence. A jagged half-crown of amber had surrounded his head like a fractured halo.

This time, however, the armor over his right arm and the draconic wing were no longer separate from Mantle.

They had merged.

The black, living stone of the Mantle and the stalwart force of Preservation intertwined without conflict, forming something that should not have existed. The armor looked less forged and more grown, shadow and amber fused with marble into a single impossible structure. At the center of his chest, embedded within Mantle itself, an amber core pulsed.

Sunny stared for half a second.

Then the world reminded him he was still being hunted.

Something was flying.

No — that word was too gentle.

Something had been thrown across the world.

His shadow sense caught it the moment it was expelled from the veil of True Darkness.

A Great Devil.

It was crashing through mountain ranges like they were decorative inconveniences. Entire peaks collapsed from the impact of its body alone, stone exploding outward as it tore across the landscape with absurd speed. Mountains toppled. The earth shattered. Shockwaves rolled outward in endless waves.

Sunny watched, dumbfounded, as the dragon continued skidding across the world like reality itself had filed a formal complaint.

It slowed.

Slowly.

Then less slowly.

Then it crashed directly into the Engine of Creation.

The impact drove the giant mech deeper into Everwinter Hill, stone exploding around it as the dragon rolled over itself, scales gouging trenches into the earth. True Darkness poured from a deep slash wound around its neck like liquid night.

Cocolia jumped over the Great Devil with effortless precision.

Apparently that was just happening now.

Sunny, meanwhile, had no such elegance.

He was too busy realizing that the True Darkness spilling from the creature completely shut down Shadow Step.

Which meant—

"Oh, come on!"

The Great Devil rolled toward him.

As it did, Sunny clumsily stumbled backward, holding out the Lance of Preservation like a man attempting to stop an avalanche with no confidence and deeply questionable life choices.

He was pushed into a corner between broken stone and dragon-scale disaster.

He felt the amber lance get pushed back a little, with something giving away.

Then, Great Devil stopped.

Silence followed.

Sunny slowly opened one eye.

Then the Nightmare Spell spoke.

[You have slain a Great Devil, Scar Of The Hollow.]

[Your shadow grows stronger.]

[You have received a Memory.]

He blinked.

Sixteen Shadow Fragments entered his soul.

He felt every single one.

Sunny stared at the dragon.

Then at the Lance in his hand.

Then back at the dragon.

’...I totally meant to do that.’

No one argued.

Excellent.

Despite the absurdity of the moment, he knew exactly why he had come here. He might not be able to use Shadow Step. But now, he had something better.

A Great Rank meat shield.

Sunny smiled slowly as he raised the Lance of Preservation.

Cocolia, advancing through the spreading True Darkness, glanced upward.

The Engine of Creation was waking.

Separated from Sunny and half-blinded by the darkness, unable to clearly perceive him, she did not understand what was happening.

Sunny pressed himself against the scaled corpse of the Drake Devil and grinned.

Inside the Engine of Creation, buried deep within its impossible structure, the single Supreme Soul Shard Clara had used in its creation pulsed.

Its systems awakened — not to fight, but to die at the Will of the treacherous Lost From Light.

A chain reaction began. Ancient power fed into ancient power, energy collapsing inward as the mech’s impossible heart prepared for catastrophic failure.

Sunny closed his eyes.

’Engine of Creation... self-destruct.’

The pulse intensified.

Cocolia, none the wiser, was still moving forward.

Then the world ended.

The detonation expanded with such violence that language became inadequate. Light erased shape. Sound ceased to matter. Fire, force, and Destruction bloomed outward like the birth of a second sun.

The explosion swallowed everything.

Mountains became dust before the shockwave even arrived. Stone ceased to be stone and became memory. Snow became steam. The sky itself seemed to ignite.

The blast expanded so far, so violently, that even in space, far above Jarilo-VI, IPC employees looking down from their ships turned toward the frozen world below as a blinding light erupted across its surface.

For one impossible moment — the dead world looked like a star.