Fate's Slave - Shadow Slave X Honkai Star Rail

Sunny and the stygian courser continued their battle in the darkness of the Sky Below, then fell on the swaying surface of a heavenly chain. Turning into swift shadows, they clashed again and again as they glided across its length with terrible speed, ripping each other’s souls to shreds.

Traversing many kilometers in a matter of a dozen heartbeats, they emerged from the shadows and shot upward, then crashed on the surface of the next island, wrecking and Destroying anything that appeared in their way.

The courser rammed Sunny again and again, carrying him further and further away through the night, not giving Saint and the Soul Serpent any chance to catch up. The stallion used his devastating hooves, his adamantine horns, and his sharp fangs... anything he had to deliver as much pain and damage to the wicked, tenacious, hateful enemy of his.

But Sunny was consumed with the same murderous fury. He returned the favor with his weapons, his claws, and his own fangs and horns as well, forgetting everything except for the crazed desire to obliterate his foe.

They rolled across the unfamiliar island like a wave of Destruction and flew high into the sky — Sunny with the help of the Dark Wing and the Heavenly Burden, the Terror with the help of nothing but the force of his hind legs and the terrifying range of his dashing jump.

His fangs caught the fragile fabric of the transparent cloak, tearing it apart, and then both of them plummeted down once more, landing on another chain and instantly submerging into shadows.

Just like that, they fought without stop, overwhelmed by the maddening desire to Destroy the enemy. When they clashed in their corporeal forms, Sunny was always on the losing side, receiving more wounds and being thrown around like a tattered rag doll.

However, when they became shadows, he held the advantage. Despite the fact that the black steed was three whole Classes ahead of him, they were of the same Rank. And while the courser was a more ancient and powerful Shadow...

Sunny was a divine one.

Suffused with the Essence of divinity, each of his attacks dealt more damage, and that damage was far more terrible, as well. His shadow form, while much smaller, was far more fathomless and resilient. Held together by the bond of a True Name, his soul was much harder to Destroy.

’Hey... what are you doing?’

They fought, and fought, and fought, flying through the night as their bodies became broken and bloodied, and their souls became tattered and torn.

And yet, the Gloomy shadow did not move to assist its master. Instead, it seemed to keep changing in shape for no apparent reason.

Sunny had never encountered this before. He had planned to use the Destruction to kill the steed, but he supposed the Preservation would have to do...

Sunny staggered forward, drunk on pain and wrath, when the Gloomy shadow suddenly stirred.

It twisted around Sunny’s body, sinking into him like a tide of ink.

His limbs froze for an instant, and then, power surged.

His flesh shuddered, groaning as if it was about to split apart. Golden cracks spread across his obsidian skin, gleaming like molten veins. Where before his monstrous frame had been only dark and savage, now it was fractured, filled with light, as though something within was too vast to be contained.

His four arms trembled. His claws... they no longer looked like claws at all. They burned with radiant arcs of cyan and gold, brimming with corrosive Essence. Each jagged movement he made tore the air itself apart, leaving glowing scars hanging in the night.

Sunny raised his head.

His black eyes were gone. In their place burned two radiant suns, merciless and cold.

The stygian courser faltered for the first time, sensing the wrongness that had taken root in its enemy. Its hooves ground sparks from the chain, its mane whipping like liquid night... and still it charged.

Sunny met it halfway.

There was no thought. No calculation. No strategy. The boy was gone, drowned beneath the tide of Destruction. What remained was a force, pure and unrelenting, that sought only to annihilate.

His claws tore through the stallion’s horns, shattering one into fragments of shadow. The next blow ripped through its chest, each golden crack along Sunny’s body blazing as if feeding on the ruin he wrought.

The courser shrieked, its body bursting into motes of black flame. Yet it did not retreat — it rammed into him again, tearing chunks from his flesh with its fangs.

Neither yielded.

The island beneath them split apart as their battle raged.

And still, they fought.

The steed was a Terror, a shadow born of ancient darkness. Sunny was a divine shadow, now corroded by something even greater, something that blurred the line between man, monster, and Destruction.

Golden cracks spread wider. His movements grew more erratic, each strike more violent than the last. He could no longer tell where his body ended and Destruction began.

And in that maelstrom of ruin, there was only one certainty:

Either Sunny or the courser would cease to exist.

The crushing blow landed squarely on the Terror’s skull.

There was a thunderclap, a shockwave, a surge of searing agony that tore through both their souls. The black steed collapsed onto its knees, cracks of golden light spiderwebbing through its shadowy body as if the Destruction inside Sunny had forced itself into the stallion’s flesh.

But it did not die.

The courser roared, a sound that shattered stone and split the air, and in that roar was more than rage — there was grief, fury, despair, all twisted together into an endless dirge. Its horns swept upward, tearing through Sunny’s ribs, ripping chunks of his body apart.

Sunny did not care.

There was no thought left in him, only instinct. Instinct that twisted, sharpened, and grew with each exchange. Shadow Dance surged through his distorted mind — wild, half-mad, but sharper than ever before. Each time the stallion moved, he moved. Each time it struck, he struck. Each breath, each twitch, each desperate lunge of the beast was mirrored, studied, and devoured by the divine shadow.

He recalled everything he could about the endless stream of nightmares... every torturous death, every indescribable torment, every excruciating loss he still remembered... and how his enemy had been in those vile dreams.

He remembered a similar deserted island, centuries ago, where the Shadow Lord said his last goodbye to his faithful steed, and their exhilarating ride across the night skies just before that.

He felt it... the rage, the hatred, the dark resolve... but also, deep underneath it, boundless loneliness, sorrow, and longing.

Ah... what a terrible Fate it was, for a shadow to walk the world without its master...

He saw himself wandering across the ruins of the Kingdom of Hope, mournful and lost, and then returning to the now empty fortress that had once been his home... his master’s home... only to see it be overtaken and desecrated by marauding strangers.

He felt a deep, maddening rage, and gave in to this madness, letting it consume him.

And then, Sunny saw himself charging at a bloodied form of a four-armed Demon.

Sunny’s movements shifted, blurred, became heavier and faster than before. His hooves slammed into the ground in perfect rhythm with the stallion’s charge. His horns lowered, gleaming gold, to clash against black. His fangs tore, his claws raked, every strike weaving between Destruction and imitation until it was impossible to tell where the Terror ended and Sunny began.

They were one.

And in that oneness, Sunny was greater.

The golden cracks across his body flared as his arms blurred into a storm of blows, each movement thoroughly dismantling the tenebrous steed. Shadow Dance devoured the Terror, stripping its mastery, its fury, its skill, and reforging it into something sharper, crueler, deadlier.

The courser staggered, confused, enraged.

The final clash came on a swaying chain high above the abyss. Both shadows leapt, colliding in midair. The world seemed to shatter as they met.

And then, Sunny’s claws, burning with cyan-gold annihilation, pierced through the stallion’s chest and tore its soul apart. It thrashed and shrieked, before eventually dying down.

Turning his head, he stared at the dying horse, whose dreadful crimson eyes were slowly growing dim and cold.

After a while, the madness burning in them was extinguished, and a shadow of a new emotion appeared in them.

Confusion, pain... and sudden recognition.

The black steed breathed in one last time, then let out of quiet whine.

And died.

Sunny’s mind slowly returned into being, the Gloomy shadow sliding off his body as his body turned back to normal. The gold and cyan energy fizzled out into nothingness.

Sunny closed his eyes.

He was so, so tired.

’...I won.’

Well... then, maybe, it was time for him to die, too.

In the darkness, the voice of the Spell whispered into his ear, its voice soft and solemn:

[You have slain an Awakened Shadow, Nightmare.]

[Your shadow grows stronger.]

He felt a vast amount of Shadow Fragments flow into his Cores, reinforcing them, and thought tiredly:

’Strange... that doesn’t feel like just six of them...’

...But the Spell was not done speaking.

It remained silent for a moment, and then said:

[...You have received a Shadow.]

[Your Aspect Legacy mastery level has increased.]

[You have received the right to claim a Legacy Relic.]

Sunny weakly tried to smile.

’Such great news... this would have been great, if I was not dying.’

And then, a strange sound invaded his ears. It sounded like... like... the rustle of sails...

[...Your shadow is overflowing with power.]

[Your shadow is changing shape.]

’Fu—’

Sunny released a distorted scream.