Inuyasha: Building the Dog Demon Soul Society

The Western Demon Kingdom. 

Chaos erupted within the royal palace as a horde of demons scrambled in panic, their frantic movements spurred by the towering inferno consuming one of the grand palaces. Most of them were dog demons, their howls echoing through the night as they desperately tried to contain the blaze. 

"Hurry! Extinguish the flames before it spreads!" 

"The fire's too intense! If we don't act now, the entire royal city will be reduced to ashes!" 

Amidst the chaos, a small figure sat calmly on the palace steps. His silver-white hair shimmered under the firelight, his crimson eyes reflecting the blaze. Fluffy ears twitched atop his head, and a tail swayed gently behind him. In his delicate fingers danced a flickering flame, its heat radiating with an otherworldly intensity. 

"Kotaro-sama, are you alright?" 

A gentle voice called out from behind him. Kotaro turned to see Yoko, his personal attendant and a dog demon with a kind smile. Her presence was a rare comfort in this world of chaos. 

Kotaro sighed, his voice tinged with frustration.

"I'm fine, but… I lost control again." 

Yoko knelt beside him, her voice soothing. "Kotaro-sama, you're still young. Struggling to control your demonic energy is natural. Don't be too hard on yourself." 

Her words were meant to comfort, but Kotaro couldn't shake the guilt. His innate power was both a blessing and a curse. 

"Kotaro-sama," Yoko continued, her smile warm,

"you're incredibly gifted. To be born with such powerful flames—you're destined to become a great demon." 

Before Kotaro could respond, the sound of approaching footsteps echoed through the courtyard. Several armored demons approached, their voices respectful yet urgent. 

"Kotaro-sama, Lady Ryukotsusei has summoned you. Once the fire is extinguished, we'll begin rebuilding your palace." 

Kotaro nodded, his expression unreadable. "Understood. Let's go." 

As he stood, he glanced down at his small, furry feet and sighed inwardly. 

"Sigh…"

Even after three years in this world, he still wasn't used to it. Reincarnated as a three-year-old child, he was still in the infancy stage by demon standards—barely past the equivalent of a human baby's first month. 

To his surprise,

Kotaro had been reborn into the world of Inuyasha, as the second son of the great demon lord Toga and Lady Ryukotsusei, making him the younger brother of the infamous Sesshomaru. 

Fortunately, Kotaro had been born with an innate ability: a powerful demonic flame.

This was likely due to a mutation in his inherited dog demon bloodline. While he bore the signature silver-white hair of the dog demons, streaks of crimson ran through his locks. His face was adorned with intricate demonic markings, and the crescent moon symbol—a mark of the highest nobility among dog demons—rested on his forehead. 

But that wasn't all. 

What frustrated Kotaro the most was his physical form. Despite being a pure-blooded dog demon, he hadn't been born in a fully humanoid form. The tail was manageable, but the fact that his legs were still those of a beast was a constant annoyance. 

According to demon lore, it would take him until the age of twenty to develop human-like legs and another decade to fully transform his ears. That meant he had over two decades to endure in this awkward state. 

While demons lived for centuries, making a few decades seem trivial, Kotaro couldn't shake the discomfort of his beastly form.

His innate demonic flames, though powerful, were equally troublesome. Without proper control, they could erupt uncontrollably, causing widespread destruction. 

Arriving at Lady Ryukotsusei's chambers, Kotaro barely had time to speak before his mother scooped him up, showering him with affectionate head pats. 

Kotaro sighed inwardly. "I'm a dog demon, not a puppy!"

"Little Kotaro, causing trouble again?" Lady Ryukotsusei teased, her voice laced with amusement. "You need to learn to control your flames, my dear." 

Kotaro could only groan internally. "If I could control them, do you think this would've happened?"

"This is the third time this month,

she continued, her tone light but chiding. "If this keeps up, your father's wealth won't be enough to rebuild your palace." 

Speaking of Toga, Kotaro couldn't help but feel his father was an absentee parent.

Always off waging wars, he rarely spent time at home. Even when he did return, he barely spared a moment for his family. 

"Mother, I'm sorry. I'll practice harder," Kotaro promised. 

Lady Ryukotsusei chuckled.

"Silly child. At your age, all you need to do is eat, sleep, and grow. The flames will come under control in time." 

She pinched his chubby cheeks, her eyes sparkling with affection.

"So adorable…" 

Kotaro couldn't help but wonder if his mother had children solely for their cuteness. Was he just a living doll to her? 

"Mother, that hurts…" 

"Alright, alright. You must be hungry, little one." 

With that, she carried him into her chambers, his small hands clutching her robes. Despite being three years old, by demon standards, he was still an infant. His meals consisted of his mother's milk,

essential for his growth and development. 

Though embarrassed, Kotaro knew it was necessary. The sooner he grew, the sooner he could shed his beastly form. 

After a hearty meal, Kotaro let out a small burp and was gently laid on a soft bed. Lady Ryukotsusei patted his back until he drifted off to sleep. 

[Great Sage: Warning. The demonic flames within the host are draining energy, severely hindering physical development. Should this be suppressed?] 

The sudden voice jolted Kotaro awake. 

"What was that?" 

[Great Sage: Introduction. This skill is known as the Great Sage.] 

Great Sage? 

[Great Sage: This skill is a gift bestowed upon the host by the world.]

The world?

[Great Sage: This query cannot be answered.]

Kotaro's mind raced. "Great Sage… Isn't that the skill from "That Time I Got Reincarnated as a Slime? 

[Great Sage: Analysis complete. The situation aligns with a 99% probability.] 

After three years of reincarnation, Kotaro had finally received his gift—not a system, but a skill. 

Was this… a blessing in disguise?

***

The forest was silent, save for the faint crackling of flames that surrounded the small figure of Kotarou, a young half-demon with crimson eyes that glowed faintly in the moonlight. His mind was racing, not just from the excitement of his newfound power, but from the revelations of the Great Sage, a skill that had awakened within him. 

"Great Sage," Kotarou muttered under his breath, his voice a mix of curiosity and determination. "If this skill is truly from that world, then it must be as powerful as they say." 

He had heard tales of the Great Sage—a skill that granted its user unparalleled intelligence, analytical prowess, and the ability to process information at an inhuman speed. Now, it seemed, he had inherited a version of it. 

'Great Sage,' he thought, his mind reaching out to the skill. 'What are your abilities?' 

Kotarou needed to know if this skill was as overpowered as the one wielded by that slime from another world. If it was, then his path to power would be far smoother than he had anticipated. 

[Great Sage: The effects of this skill are as follows.] 

[Thought Acceleration: Increases the user's perception speed by a thousandfold, allowing for rapid thinking and decision-making.] 

[Analysis and Appraisal: Analyzes and identifies unknown objects or phenomena.] 

[Parallel Processing: Separates and processes multiple tasks simultaneously, and can link with other skills.] 

Kotarou's eyes narrowed as he processed the information. 'Parallel Processing? What does that even mean?' 

[Great Sage: For example, it can analyze an enemy's demonic energy, aura, and weaknesses. Once the analysis is complete, it can calculate the optimal strategy for the user to achieve victory.] 

Ah, now that made sense. This wasn't just a passive skill—it was a tool for domination. Kotarou's lips curled into a smirk. 'So, it can dissect my enemies and hand me the perfect plan to crush them. Not bad.' 

[Omniscience: Gathers information about all phenomena in this world that are not shielded.] 

'Omniscience?' Kotarou raised an eyebrow. 'What does that mean?' 

[Great Sage: The user can think of it as an automatic search function for the world's basic knowledge, akin to an encyclopedia.] 

Kotarou nodded slowly. 'So, it's like having a library in my head. But what if something is shielded?' 

[Great Sage: Correct. Just as an encyclopedia is not all-knowing, basic knowledge can be obtained, but deeper or hidden knowledge remains inaccessible.] 

[Great Sage: These are the current effects of this skill.] 

Kotarou exhaled, his breath visible in the cool night air. The skill was impressive, no doubt. It was almost identical to the one possessed by that slime from another world. The Great Sage had said the similarity was 99%, and while there were minor differences, they didn't seem to matter much. 

But there was something else nagging at him. 

'Great Sage,' he thought, his tone sharp. 'Earlier, you mentioned a warning. What was that about?' 

[Great Sage: Warning. The demonic flame within the host's body is siphoning energy. This behavior is severely hindering the host's growth. Should it be stopped?] 

Kotarou's eyes widened. The demonic flame—his birthright, his curse—was stealing his energy? No wonder his flames had gone out of control three times in the past month. It wasn't just his lack of control—it was this parasitic flame leeching off his life force. 

'Stop it,' he commanded, his voice cold. 'Now.' 

[Great Sage: Restricting the demonic flame's energy absorption.] 

[Restriction complete.] 

Kotarou felt a subtle shift within him, as though a weight had been lifted. The flames around him flickered and dimmed, their chaotic energy subdued. 

'With this, the flames shouldn't go out of control anymore, right?' 

[Correct. By limiting the demonic flame's energy intake, it will grow at the same rate as the host. Based on the host's current growth rate, the flame will no longer be uncontrollable after three months.] 

Three months. Kotarou's jaw tightened. For a demon, three months was nothing—a mere blink in their long lives. But for him, it felt like an eternity. He had plans, ambitions. He couldn't afford to wait. 

'Great Sage,' he thought, his voice firm. 'Is there a way for me to gain control of the flames faster?' 

When Kotarou first arrived in this world, he had been filled with excitement. The idea of wielding demonic flames and unleashing devastating attacks like those he had seen in anime had thrilled him. But reality had been far harsher. Controlling the flames was like trying to tame a wild beast—it resisted him at every turn. 

[Calculating methods to enhance demonic energy. Begin?] 

'Begin,' Kotarou commanded without hesitation. 

[Analysis initiated. Conducting a

comprehensive scan of the host.] 

[Analysis complete.] 

[Race: Dog Demon] 

[Age: Three years and seven months] 

[Status: Dog Demon Infant] 

[Talent: Nameless Demonic Flame] 

[Initiating demonic energy enhancement calculations.] 

[Calculating. Extracting a portion of demonic energy for experimentation. Requesting activation of Thought Acceleration to expedite the process.] 

'Thought Acceleration? Fine. Activate it.' 

[Activating Thought Acceleration.] 

In an instant, Kotarou's world changed. His senses sharpened to an almost unbearable degree. The faint scent of grass and earth filled his nostrils, each blade of grass distinct in his mind. The dust particles floating in the air became visible, each one a tiny world unto itself. 

Within his mind, a red light began to trace intricate patterns, forming the outline of a transparent human body. The light flowed through the meridians, mapping out the pathways of his demonic energy. 

[Warning: The host's current physical condition cannot withstand 1000x Thought Acceleration. Reducing intensity.] 

[Thought Acceleration: 500x] 

[...] 

[Unable to sustain. Further reduction required.] 

[Thought Acceleration: 300x] 

[...] 

[Reducing intensity...] 

[Thought Acceleration: 20x] 

[Host can sustain 20x Thought Acceleration. Limiting to 20x.] 

The hyper-awareness faded, leaving Kotarou feeling as though the world had become dull and blurry. The stark contrast was jarring, but he quickly adjusted. 

The red light in his mind now moved at a slower, more manageable pace. 

'So, my body can't handle the full power of Thought Acceleration yet,' Kotarou mused. 'But if I can grow stronger, perhaps one day I'll be able to sustain it.' 

[Calculation complete.] 

[Pure Demonic Energy Refinement Method: Accelerates the host's ability to refine nutrients from breast milk, extracting energy to enhance demonic energy and promote physical growth.] 

Kotarou blinked. 'Refining breast milk? Seriously?' 

[The analysis concludes that refining breast milk is the fastest and safest method for the host to increase demonic energy.] 

[This is the optimal solution calculated by this skill. The host is advised not to doubt it.] 

Kotarou sighed, running a hand through his hair. 'Well, it's not exactly what I imagined, but I'll give it a try.' 

He focused on the newly acquired method in his mind. It involved circulating demonic energy within his body to speed up the digestion of breast milk, thereby enhancing his demonic energy. 

Thanks to the brief activation of Thought Acceleration, his senses had been heightened, allowing him to detect the faint traces of demonic energy within him. Even though Thought Acceleration had been deactivated, this newfound sensitivity remained. 

It was like learning to swim—once you knew how, your body never forgot. 

'Let's see how this Pure Demonic Energy Refinement Method works,' Kotarou thought, closing his eyes and beginning to focus. 

The faint traces of demonic energy within him stirred, following the pathways outlined by the Great Sage. Slowly but surely, he could feel the energy circulating, growing stronger with each cycle. 

The journey to mastering his demonic flames had just begun, and Kotarou was ready to embrace it. 

---

The forest was silent once more, save for the faint crackling of flames that now burned with a controlled intensity. Kotarou stood tall, his crimson eyes glowing with newfound determination. 

The Great Sage had given him the tools he needed. Now, it was up to him to wield them. 

And he would. No matter the cost.