Chapter 1: The Accidental Demon
The oppressive darkness of the cave clung heavy, broken only by the ragged, desperate breaths of a boy. "You evil ghost, I will kill you!" he rasped, his voice raw. His small, 14-year-old body was a tapestry of fresh scars, a testament to a brutal struggle. Nearby, the lifeless form of a demon lay slumped, its presence chilling the air.
Opposite him, however, stood another demon, one hand freshly severed but now strangely reforming, confusion etched on its grotesque face. This was no ordinary demon. Within its monstrous frame resided the soul of Shiki, a "blue star native," yanked from his own world and flung into this brutal existence.
Shiki's consciousness, still reeling from the sudden, agonizing pain of his re-severed limb, processed the scene before him. The dead demon, the boy in the familiar uniform, the distinct hilt of a Demon Slaying Blade – a chilling realization dawned upon him. He had transmigrated into the world of Demon Slayer, and he, Shiki, was now one of the very creatures humanity considered its mortal enemy. The boy, a mere child, was fighting him with his last reserves, his youthful face twisted in determination.
"I will kill you, evil demon!" the boy screamed, gasping for air. "Flame Breath, First Form!"
Shiki felt the phantom pain in his now recovered, then instantly re-severed hand. The boy's sword arced towards his neck with terrifying speed. With an instinctive surge of power, Shiki pushed the boy away, just a few meters. But fate, or perhaps misfortune, had other plans. The boy, off-balance, stumbled backward and impaled himself on a sharp, protruding branch, which pierced his chest with a sickening thud.
Shiki let out a ragged sigh of relief, but the momentary reprieve was shattered by the distant sounds of commotion – dozens of footsteps, approaching fast. Without hesitation, he snatched the demon-slaying sword from the fallen boy's grasp and bolted. Westward he ran, his new demonic physiology allowing him to cover five hundred meters in mere seconds, leaving the sounds of the approaching Demon Slayer Corps behind.
He soon neared a village, its warm lights a stark contrast to the darkness he had just escaped. Choosing a house on the secluded outer edge, he leaped effortlessly over its fence. A wave of human scent assailed him, and a primal hunger flared within. To quell it, he plunged the demon-slaying sword into his own hand. The searing pain, sharp and immediate, was enough to suppress the ravenous craving.
He pushed open a door and found a small girl, no more than ten years old, bound by chains. Her wide, innocent eyes met his, and with surprising courage, she extended a piece of bread. "Brother, are you hungry?" she whispered.
Shiki, taken aback by her simple kindness, gently shook his head. "No," he replied, his voice rough.
"Do you want to eat me?" she asked, her voice barely audible.
"I don't eat good little girls," Shiki said, a surprising tenderness in his new, clawed hand as he gently patted her head. The girl, Kanao, flinched slightly before leaning into the warmth. It was a sensation she had rarely, if ever, known. Her parents were cruel, her siblings long dead from abuse, and she, with her sharp perception, had only survived by evading their beatings. Now, they planned to sell her to pay off gambling debts.
"What's your name, little one?" Shiki asked softly.
"Kanao," she whispered.
He placed his hand on her head again. "I will take care of you from now on." With surprising ease, he snapped the iron collar from her neck and released her. He knew the tragic fate of Kanao, her future as a broken, coin-flipping girl. Pity stirred within his new demon heart, and he resolved to save her. Hearing his gentle words, words of care she had never received, Kanao began to cry, burying her face in his arms.
After several minutes of silent tears, Shiki handed her the bread. As she quietly ate, he sat in the darkest corner of the room. "System, open," he commanded. He had heard a faint voice of activation when he'd killed the demon slayer, but there had been no time to investigate. Now, he was safe.
A translucent panel materialized before him. "What is your work?" Shiki asked the ethereal presence.
"This is the Evolution System, Host. You can evolve infinitely."
Shiki felt a surge of excitement. "Is there a novice gift pack?"
"Host, please check your inventory."
He accessed the inventory, finding a single Lottery Ticket. "System, what is this for?"
"You can gain templates from other worlds."
His excitement soared. "Use it!"
A grand wheel appeared, spinning rapidly. It slowed, then stopped on a grotesque, joker-like figure with a black jacket and two sinister black wings – a creature that looked like it had crawled from the deepest pits of hell. A sudden, electrifying realization struck Shiki. "Is this… Ryuk from Death Note? A powerful Shinigami?"
"Integrate it!" he commanded instantly.
The wheel dissolved into blinding light, surging directly into Shiki's body. An overwhelming wave of power washed over him. His entire being morphed, transforming. He shot up in height, reaching almost 7.1 feet, towering over normal humans. His ragged clothes dissolved, replaced by a sleek black jacket and black pants. His hair lengthened, becoming a cascade of black, giving him a dangerous, otherworldly aura. He felt an undeniable surge of vitality, and an odd sensation at his back.
He found a makeshift mirror and stared at his reflection. His appearance was undeniably that of Ryuk, the Shinigami, but his own gentle face remained, framed by the long black hair. His eyes, however, were now pits of darkness, as void-like as Ryuk's, lending him a dangerous yet strangely charming allure. His hands had transformed into sharp, clawed digits.
He reopened his system panel:
Name: Shiki
Template: Shinigami (Powerful)
Skills:
* Super Strength
* Super Speed
* Flight
* Immortal Body of Shinigami
* Invisibility
* Intangibility (You can pass through objects easily)
Shiki frowned. "Wait, two more things… Where are my Shinigami Eyes and the Death Note?"
The System replied: "Only 60% of the template was merged. Host must collect souls to increase or evolve the template. With souls, Host can increase template progress or evolve yourself infinitely. Number of Souls: 0. Cannot progress the template or evolve current skills and body."
Kanao, who had been watching in astonishment, finally spoke, her cute face beaming, eyes wide like stars. "Brother, are you powerful now?" she asked, without a hint of fear.
Shiki smiled. "Yes. Now, brother doesn't have to eat humans. He can live with Kanao, even in the sun."
Kanao jumped in excitement, "Brother is good!" Seeing her joyous smile, a genuine, gentle smile touched Shiki's transformed face.
The moment was shattered as the front door creaked open. "Why are you shouting so loud?!" A middle-aged man, Kanao's father, stepped into the room. Kanao immediately cowered behind Shiki, fear returning to her eyes. Shiki knew who this man was. He swiftly moved, covering Kanao's eyes with one hand, and with the other, he cut the man's throat. "Don't worry, I'm here," he murmured. Kanao, surprisingly, showed no reaction to her father's death, simply ignoring his crumpled form.
A small ball of shimmering blue light appeared above the dead man. Shiki reached out and touched it.
Ding! Host has gained one soul!
The next morning, as they prepared to leave the house, Shiki considered their predicament. "System, can I change into a human form?" Carrying Kanao while invisible would be suspicious; people would think Kanao was flying. He also desired to live a normal life with her.
Ding! Does Host wish to use one soul to gain a skill to transform into human form at any time?
"Yes," Shiki confirmed.
A surge of new knowledge flooded his mind. His body began to shift, to shrink, transforming. In moments, he stood as a young man of sixteen or seventeen years old. His eyes were dark black pupils, his hair long and black, perfectly complementing his new black clothes.
Kanao gasped, astonished once more. "Big brother changed into a human!" She launched herself into his arms, hugging him tightly, a profound sense of security washing over her. Together, they left the house, left the village behind, and set off towards the distant town.