Fate's Slave - Shadow Slave X Honkai Star Rail

Sunny had imagined this moment more times than he would ever admit.

Not the setting — not the shattered shoreline of Scalegorge Waterscape, not the looming silhouettes of two Saints tearing apart the world behind him — but the feeling.

The anticipation.

The sharp, electric hum in his veins that only one opponent had ever managed to evoke. Completely unlike his hunger to kill those he wanted to see killed...

He just wanted to fight. To fight a fight with no end in sight.

’Oh, Yanqing...’

Back when they had both been Awakened and not Ascended, the final round of the Dream Tournament had been a slaughterhouse disguised as spectacle. Sunny had stepped into that arena wearing Mongrel’s mask, hiding behind a false name and a distorted voice. Yanqing had entered openly — proud, composed, terrifyingly young.

The duel had been beautiful.

He had mirrored Sunny’s footwork, dissected his angles, adapted to his tempo in real time. Every adjustment Sunny made was reflected back at him — refined, sharpened, weaponized.

Shadow Dance had answered.

Sunny had shadowed Yanqing in return, absorbing his rhythm, folding it into his own evolving pattern. They had climbed together in a spiral of escalating brutality, each forcing the other to grow faster than thought.

Sunny had won.

Not because he was better.

Because Yanqing had run out of Soul Essence.

The first strike of the match and the last had both belonged to Sunny.

Now they were Ascended.

Sunny felt his lips stretch into a grin beneath the horned mask.

He had almost forgotten that this was actually Dan Heng’s homeland. Almost forgotten that the man currently summoning storms behind him was, apparently, a Saint — or something dangerously close to it.

Didn’t matter.

Yanqing stood in front of him.

And that was enough.

He rolled his shoulders once, feeling the weight of Soul Serpent resting across them in the shape of a massive odachi forged from hell-black onyx. The blade thrummed faintly — tired, but eager. He had spent more Shadow Essence than he liked healing it earlier.

He was low.

He was fatigued.

Perfect. That was when he was at his best — a feral raccoon clawing for scraps in an empty trash can.

He wouldn’t use his Aspect. Just his blade, his armor and the enchantments imbedded in it, and the power coursing through his very soul.

He took a single step forward—

—when the world exploded behind him.

A crack like the sky splitting open reverberated across the beach.

Sunny flinched and twisted around just in time to see a bolt of blinding lightning tear through the air, hurled from Dan Heng’s outstretched hand. It struck a limestone outcropping where Blade had stood a heartbeat before.

The rock didn’t shatter.

It disintegrated.

Reduced to drifting dust in a single, merciless instant.

Sunny blinked.

”...Right.”

Two Saints.

With history.

Behind him.

He slowly turned back toward Yanqing.

The young Master had also glanced over his shoulder. For the briefest moment, shock flickered across his face as a tidal surge rose and collapsed in the distance, swallowing half the shoreline before retreating.

Their eyes met again.

Understanding passed between them.

Unlike the sterile environment of the arena — besides the flower petals on the floor — they now had to survive a new addition to their date with death.

The apocalypse. In the form of two men.

Yanqing’s lips curved.

Sunny’s grin widened beneath the mask.

They moved at the same time.

Sunny dashed forward, sand exploding beneath his boots as he adjusted his weight — lightening himself mid-stride to accelerate beyond what his muscles alone could manage.

Yanqing lifted a hand.

Teal light flared.

An identical black odachi formed in his grasp, forged from luminous essence — a mirror of Soul Serpent’s current shape.

Behind him, a dozen weapons materialized: spears, swords, curved sabers, floating in a silent halo.

Sunny laughed, the sound coming out hauntingly due to Weaver’s Mask.

”Oh, that’s nothing!”

They collided.

Steel shrieked.

The impact vibrated up Sunny’s arms, forcing him to immediately increase his weight to anchor himself. Yanqing had matched his initial strike perfectly — angle, speed, timing.

Of course he had.

Yanqing’s eyes gleamed with focus, not madness like Blade’s — but something cleaner. Hungrier.

He pivoted, blade tracing a razor-thin arc toward Sunny’s neck.

Sunny bent backward, decreasing his weight to let momentum carry him just beneath the edge. As he snapped upright, Soul Serpent shifted.

The odachi shrank and split, flowing like liquid shadow into twin short blades.

Yanqing’s eyes sharpened.

His own odachi dissolved into ink, reforming as identical shortswords.

They clashed again.

Faster now.

Close.

Brutal.

Behind them, the shoreline convulsed as another tidal surge erupted. Blade answered with a crescent slash of crimson energy that split the wave in two, detonating it into rain and steam.

A stray fragment of lightning arced toward the ground near Sunny’s feet.

He kicked off just as it struck, the sand beneath him vaporizing.

Mid-air, Yanqing flicked his wrist.

Three of the floating weapons launched like bullets.

Sunny twisted, lightening himself further to spin unnaturally fast. One blade grazed his side. Another tore through his sleeve gauntlet. The third he deflected mid-rotation, sending it spiraling harmlessly into a collapsing rock formation.

He landed heavily, increasing his weight to crater the sand and stabilize.

Soul Serpent flowed again.

A spear.

Yanqing’s weapons shifted as he dropped his current form and conjured a spear of teal light in response.

They thrust simultaneously.

The tips met.

Essence flared violently.

Sunny felt it then — the old rhythm returning.

Yanqing wasn’t just copying the present shape any longer. If he had needed to destroy and reshape his weapons before, now he was able to replicate the [Serpentine Steel] Ability, letting him change its shape with more fluidity.

The spear dissolved mid-exchange, becoming a massive cleaver. Sunny swung downward with crushing force, increasing his weight at the apex to multiply the impact.

Yanqing’s spear liquefied into a curved saber just in time to redirect the blow rather than block it outright. The redirected force tore a trench through the beach behind him.

Five more weapons launched toward Sunny’s blind side.

He swore internally.

’I really need more hands!’

In an explosive blur of movement, Sunny swiftly parried the missile-like swords.

Yanqing capitalized instantly.

He dashed forward, blade slicing in a precise diagonal meant to bisect Sunny before he could reset his weight.

Sunny reacted on instinct.

Weight lightened.

Body twisted.

Soul Serpent elongated back into the odachi just in time to intercept.

The impact sent a shockwave rippling outward.

Behind them, Dan Heng thrust his hand skyward. The orb hovering above it spun violently as water rose in towering columns, freezing mid-air before crashing down as spears of ice.

Blade carved through them with explosive, crimson slashes that shattered the frozen pillars into lethal shrapnel.

One fragment the size of a carriage hurtled toward Sunny and Yanqing.

They both glanced up.

And moved in opposite directions.

The ice slammed into the beach between them, detonating into shards.

Yanqing reappeared through the mist first.

A straight thrust.

Sunny met it — but too late.

The tip grazed his ribs, drawing blood.

’Yes... yes...! Fabulous!’

Pain sharpened everything.

Soul Serpent shifted again — a heavy hammer this time. Sunny swung low, aiming to shatter Yanqing’s stance entirely.

Yanqing’s weapon shattered mid-block — deliberately — and reformed as a hookblade that caught the hammer’s haft and redirected it.

The hammer dissolved.

A rapier formed.

Sunny lunged.

Yanqing mirrored him.

Behind Yanqing, the floating arsenal multiplied.

Now two dozen.

Sunny exhaled slowly.

This was becoming problematic.

He couldn’t focus entirely on Yanqing. Every few seconds, a weapon would streak toward him from an impossible angle. Simultaneously, tidal waves, lightning bolts, and crimson shockwaves ravaged the battlefield around them.

He parried Yanqing’s rapier.

Dodged a projectile.

Shifted weight to tank another.

Reduced weight to slip through a collapsing rock formation as Blade’s slash obliterated it.

”Are you trying to kill me or them?!”

Sunny barked toward the chaos behind him.

A bolt of lightning answered.

Sunny sighed.

Yanqing’s expression flickered with something that might have been amusement.

They accelerated again.

Sword became glaive.

Glaive became axe.

Axe became dagger.

Each time Soul Serpent changed form, Yanqing conjured an identical counterpart within seconds — sometimes faster.

But Sunny began to notice something.

Yanqing’s copies were perfect in structure.

But not in history.

Soul Serpent wasn’t just a weapon.

It was alive.

It learned with him.

When Sunny shifted weight mid-swing, altering the arc unpredictably, Yanqing matched the movement — but not the underlying instinct.

There was the faintest delay.

A hair’s breadth.

That was enough.

Sunny pressed harder, Serpent extending into a greatsword without his command, forcing Yanqing to lean back.

Before Yanqing could fully compensate, Sunny reduced his weight to near nothing, pivoted around the young swordsman’s guard, and slashed across his shoulder.

Blood.

Yanqing skidded back, eyes blazing.

Behind them, the ocean vanished.

Not metaphorically.

Dan Heng had drawn it upward into the sky.

An entire wall of water loomed overhead as Blade carved through arcs of lightning with manic laughter.

Sunny glanced up just long enough to realize they were about to be crushed.

”...You have got to be kidding me.”

The tidal wall collapsed.

Yanqing leapt skyward, forming platforms of floating swords to escape.

Sunny reduced his weight to nothing and launched himself upward as well, using a falling slab of stone as a stepping point before increasing his weight mid-air to anchor onto another fragment.

Water roared past beneath them.

For a moment, they fought suspended in chaos.

Blades clashed atop falling debris.

Projectiles weaved through torrential rain.

Sunny felt Shadow Essence thinning inside him.

He ignored it.

One more exchange.

Just one more.

Yanqing conjured a massive greatsword.

Sunny answered in kind.

They swung.

The collision split the air.

And then—

The world went silent.

Not quiet.

Silent.

Blade stopped laughing.

Dan Heng stopped moving.

A pressure far heavier than anything before descended upon the battlefield.

Sunny felt it instantly.

His instincts screamed.

He landed on a floating shard of rock and looked toward the two Saints.

Blade stood upright, crimson aura coiling around him in tightening spirals. The golden seams of his kintsugi blade flared with blinding intensity.

Dan Heng’s horns gleamed, emerald light gathering around the orb above his palm.

Sunny swallowed.

”Oh.”

Blade’s voice carried across the devastated shoreline.

”You think this is enough, Dan Feng? Why can’t you just sit still... and die?!”

The crimson aura condensed... before exploding outwards.

Across from Blade, Dan Heng raised his hand.

The ocean answered.

And both Saints unleashed their Transcendent Abilities.

The sky tore open.