Fate's Slave - Shadow Slave X Honkai Star Rail

The battlefield did not slow so much as it shifted into a different kind of violence once Aventurine joined the fray.

Where Sunny moved like a precise executioner, carving clean lines of death through the tide of Nightmare Creatures, Aventurine brought something far less refined but no less terrifying. The man fought like a walking catastrophe, his movements loose and almost lazy, yet every casual motion carried overwhelming force. Awakened Devils that could shrug off coordinated assaults from squads of soldiers were reduced to pulp beneath his blows, their bodies collapsing into shattered masses before they could even register what had struck them.

Sunny cut through a lunging creature, his blade sliding through its neck before he pivoted smoothly into another strike, severing a wing from a second Devil that had attempted to flank him. At the same time, Aventurine stepped forward and caught two creatures mid-charge, his hands closing around their skulls before slamming them together with a sickening crack that echoed across the battlefield. The impact alone was enough to rupture both bodies, sending fragments scattering across the blood-soaked ground.

Despite the chaos, their movements did not interfere with one another. There was an unspoken rhythm forming between them, a strange synchronization that allowed them to occupy the same battlefield without obstruction. Sunny’s shadows filled the gaps left by Aventurine’s brute force, while Aventurine’s overwhelming presence created openings that Sunny exploited without hesitation. It was not cooperation in the traditional sense, but it was effective nonetheless.

Sunny ducked beneath a sweeping claw, his flaming blade flashing upward as it carved through the creature’s torso. The fire burned cleanly, erasing the creeping traces of True Darkness that leaked from the wound, while his other hand drove Hail Sorrow forward into another Devil’s chest. As he twisted the blade free, he glanced toward Aventurine, irritation evident even in the middle of slaughter.

Sunny demanded, his voice sharp as he stepped past a collapsing corpse.

"What are you doing over here? My lady is holding off the damn Corrupted Saint you were supposed to deal with."

Aventurine hummed thoughtfully, his tone light as he grabbed another creature by the tail and swung it like a weapon, smashing it into two others before releasing it entirely. He replied, almost cheerfully, as he stepped forward and drove his fist through the chest of an Awakened Beast.

"Sorry about that, but I am on payroll. In any case, the situation completely changed, and communication is key."

Sunny scowled, flipping backward to avoid a snapping jaw before bringing his blade down in a clean arc that split the creature’s spine.

"And what could that possibly be?"

Aventurine’s laughter carried through the chaos, soft but unmistakably amused.

"Well, another Category 4 Gate has appeared down under."

For a brief moment, Sunny’s movements stuttered. Not enough to be dangerous, but enough for the shock to register. His shadows reacted violently to the lapse, surging outward to impale a nearby creature from multiple angles, pinning it in place before tearing it apart.

He muttered, the words slipping out before he could stop them:

"The fuck?"

Aventurine giggled, the sound strangely at odds with the carnage surrounding them. He said, brushing nonexistent dust from his sleeve as he casually sidestepped an incoming attack:

"Actually, it’s all your fault. The strings of Fate are wrapped tightly around you, completely screwing with probability. The unlikely is more likely than the likely, it seems."

Sunny clicked his tongue in irritation, already suspecting the culprit before Aventurine had even finished speaking.

Of course it was [Fated]. That damn Attribute had a habit of turning every situation into something far more complicated than it had any right to be.

He asked, tone clipped as he drove his flaming blade into the gut of a lunging Devil:

"How far is it?"

Aventurine replied casually.

"Right below."

Sunny paused just long enough for the implication to settle in. His gaze flickered briefly toward the ground beneath them, his mind already racing through possibilities as he withdrew his blade and let the creature collapse.

At the same time, Aventurine found himself in a nearly identical position, his fist embedded in the torso of another Nightmare Creature. He glanced toward Sunny, a knowing smile hidden beneath his mask and blindfold.

"I was going to ask what you thought of it..."

He said, pulling his hand free as the creature disintegrated:

"...But it looks like the two of us have come up with the same idea."

A fierce grin spread across Sunny’s face, sharp and dangerous.

"Do we? Isn’t that just super convenient?"

Aventurine tilted his head slightly, the hint of excitement in his voice becoming more apparent.

"If you would, go switch with that knight of yours. Both of your lucks will increase, it seems. I’ll hold this off until then, while Miss Clara handles the other Nightmare Gate and the evacuation. Ah... and bring the Supreme Guardian with you."

Sunny didn’t particularly like the idea of following orders, especially not from someone affiliated with the IPC, but the logic was sound enough that he didn’t bother arguing. The situation had escalated beyond personal preference, and hesitation would only make things worse.

"Fine."

Without another word, he stepped backward into the shadows.

The transition was instantaneous.

One moment he stood amidst the battlefield, and the next he emerged from the darkness behind Bronya. She barely had time to react before he grabbed her, lifting her into a princess carry with a speed that left no room for protest.

"Wha—?!"

Before she could finish, Sunny was already moving.

He sprinted forward, his steps light despite the added weight as he leapt onto the nearest structure. From there, he moved across the battlefield in a blur, bounding from rooftop to rooftop with effortless precision. The wind tore past them as he accelerated, the distance between them and the main battle shrinking rapidly.

"Where are we going?!"

Bronya shouted, her voice strained against the rushing air.

Sunny’s expression darkened slightly as he focused on the path ahead.

"To meet your maker..."

She blinked in confusion.

"Huh?"

Sunny added after a brief pause:

"Oh, right. You’re adopted."

Bronya stared at him, clearly caught between disbelief and frustration, but there was no time to argue as he reached the outer walls of Belobog. Without slowing, he ran straight up the vertical surface, his movements defying gravity as he carried her to the top.

When they reached the edge, he set her down firmly.

"No matter what, don’t leave this wall."

Bronya steadied herself, her expression tightening as she processed his words.

"What are you—"

"Make sure to keep me augmented. Otherwise, I might just die. Or run away, in which case you and all those other people die." 𝐟𝗿𝐞𝚎𝚠𝐞𝚋𝕟𝐨𝚟𝐞𝕝.𝕔𝕠𝚖

He gave her a casual salute, as if the statement carried no weight at all.

Then he leaned back and stepped off the wall, taking a leap of faith.

The fall was brief.

The moment his body made contact with the snow-covered ground below, he sank into the shadows, disappearing completely.

When he emerged again, he was no longer the same.

His form had changed, expanding into something far more monstrous. Four powerful arms extended from his body, each one capable of wielding a weapon with deadly precision. Two horns curved upward from his head while another pair jutted forward, framing a face that had lost any trace of humanity. His features were sharp, predatory, with fangs that glinted faintly in the dim light. A long tail lashed behind him, cutting through the air with controlled menace.

The Shadow Shell of the Shadowspawn Devil had returned.

A moment later, tenebrous onyx armor encased his transformed body as the Marble Shell shifted into its Mantle form, reinforcing him further. Memories appeared in his hands in rapid succession, each one settling into place as if it had always belonged there.

The Midnight Shard rested in one hand, its polished blade gleaming faintly despite the surrounding darkness. The Dusk Shard formed on another arm, its weight grounding his stance. Hail Sorrow remained in his grip, its presence as ominous as ever, while the Lance of Preservation manifested with a molten glow that contrasted sharply against the cold environment.

At his side, the Shadow Lantern and Dying Wish reappeared, their presence completing the array.

Ahead of him, Saint and Cocolia clashed in a storm of ice and steel.

Saint moved with relentless precision, her cape of darkness billowing behind her as she met Cocolia’s attacks head-on. The frozen demon responded with equal ferocity, her spear carving through the air as waves of ice erupted with every motion.

Sunny did not hesitate.

He surged forward, his massive form cutting through the snow as he closed the distance in seconds.

At the same time, Saint turned.

Their movements aligned perfectly.

As they crossed paths, Saint reached out and took Dying Wish from Sunny, attaching it to her armor without breaking stride. The Memory responded instantly, its accumulated charge flowing into her body as her wounds began to close. The cracks in her armor sealed, the exposed traces of ruby dust disappearing as her form stabilized.

Two new Memories manifested alongside her.

Morgan’s Warbow appeared in her grasp, its black frame contrasting sharply against the crimson string that hummed with restrained power. An arrow formed alongside it, its presence carrying a weight that suggested devastating force.

At the same time, four shadows rippled outward from her body, flowing toward Sunny.

They wrapped around him, merging with his form and amplifying his presence severalfold.

The effect was immediate.

Power surged through his body, his already overwhelming strength pushed to an entirely new level as the augmentation took hold.

Cocolia turned toward him just as he arrived.

Her spear lashed out, a streak of frozen destruction aimed directly at his core.

Sunny met it head-on.

Hail Sorrow collided with the spear in a clash that sent a shockwave tearing through the battlefield. The impact shattered the ground beneath them, ice and stone fracturing outward as the two forces met in a violent stalemate.

For a brief moment, neither moved.

Then Sunny’s grin widened as the Extraordinary Rock, which was lodged in his false throat, echoed his voice:

"Let’s finish what we started!"