[Blood Resonance].
The effect of this ability was even more absurd than Kōbe Hikaru had imagined.
And it certainly did not disappoint him.
The moment he struck his first blow and the first drop of blood splattered into the air, countless new perspectives suddenly appeared in his vision.
Those perspectives came from the blood drops.
Every single drop of blood became his eyes.
In all directions, a full three hundred and sixty degrees with no blind spots.
To his back left, a Snake-Body Demon was gathering strength to charge; to his upper right, a Bird-Head Monster was diving down with its talons bared; straight ahead, three Green-Skin Demons were flanking him with bone clubs raised.
He could see it all with absolute clarity.
‘This thing…’
Hikaru wasted no time; his body reacted before his mind even processed the thought.
He took a step to the left and swung his blade backward and upward.
*Squelch.*
The edge of the blade sliced precisely into the Snake-Body Demon’s vital spot.
Its serpentine body continued to rush forward, but its head was already tumbling across the ground.
There was no need to look back.
Because the splattering blood told him the Bird-Head Monster was already two feet above his head.
Hikaru leaned forward and thrust the tip of his sword skyward.
In a normal battle, this move would be tantamount to suicide—turning his back to the enemy, blade pointed up, completely abandoning all defense.
But he could see.
The tip of the sword pierced through the Bird-Head Monster’s lower jaw and burst out from the top of its skull.
The yōkai’s sharp talons scraped past his back, tearing off only a few broken scales of his armor.
A hair’s breadth away.
Hikaru flicked his sword, sending the Bird-Head Monster’s corpse flying toward the three Green-Skin Demons directly in front of him, making them stumble.
He seized the opportunity and dashed forward, delivering three strikes.
Three heads fell to the ground.
‘Satisfying.’
For the first time in battle, Hikaru felt completely at ease.
Not because his enemies were too weak, but because he could see everything.
The blood was his scout.
As long as there was blood on the battlefield, he was the absolute master of this domain.
And on this current battlefield, the one thing they certainly did not lack was blood.
“Kill him!”
The Green-Skin Demon boss roared while hiding behind the yōkai horde.
More yōkai surged forward, filling the gaps left by their fallen comrades.
Hikaru did not stop.
He charged headlong into the swarm.
It was a crazy choice.
But [Blood Resonance] gave him the capital to be crazy.
The blade flashed.
One strike, two strikes, three strikes.
Every flash of the blade brought forth a rain of blood, and every shower of blood expanded his field of vision even further.
He weaved through the yōkai horde like a fish darting through water.
Not a single yōkai could ambush him.
Because their blood had long since betrayed their positions.
Thirty breaths passed.
Another twelve yōkai fell.
Hikaru’s swordplay grew faster, his movements increasingly fluid.
The strength of these yōkai varied greatly.
Some died in a single strike, some required two, and some could even block his attacks.
There was clearly a disparity between them.
Where did this disparity lie?
It lay in their morphological differences—in the degree of mutation from their original forms before they became yōkai.
Some were merely ordinary deformed creatures; their skin changed color, they grew sharp claws, and that was it.
Others were clearly mutated much more thoroughly, sprouting horns, scales, tails, and other organs that shouldn’t exist on their bodies.
There were also a rare few whose bodies were a full size larger than their peers, their movements far more agile and ferocious.
This was the essence of yōkai.
Transformation.
From weak to strong, from mortal to yōkai.
Every transformation was an evolution, and every evolution made a yōkai stronger.
Over the past three months, Hikaru had gradually figured out this system.
A yōkai’s growth was divided into four major stages, known as the Four Transformations.
The first stage was called Body Transformation.
This was the most fundamental change, referring to the mutation of physical structure.
Wolves growing horns, snakes sprouting legs, insects developing wings, fish forming claws.
These visible, localized mutations were the defining traits of Body Transformation.
Once an ordinary beast or wandering soul absorbed enough demonic aura, it would begin its Body Transformation.
Body Transformation was divided into six minor stages, corresponding to the limits of the limbs, head, and torso that a normal creature could directly control.
These were known as the Six Stages.
With every stage completed, the body would gain a new mutated trait, and its strength would increase accordingly.
Some were obvious, some were not.
Some even manifested in the muscles and bones, showing no external signs but granting extraordinary strength.
All of these variations existed.
A yōkai that completed all Six Stages could attempt to break through to the next major phase—Quality Transformation.
Quality Transformation generally corresponded to changes in mass and volume.
It was a step beyond localized changes, becoming a holistic transformation.
At this stage, a yōkai could alter its body size.
It could grow larger or shrink smaller at will, ultimately achieving Perfect Mass based on its original species.
After Quality Transformation came Aura Transformation.
Aura Transformation was a further metamorphosis built upon Perfect Mass.
Hikaru wasn’t entirely clear on the specifics, as none of the yōkai he had encountered had reached this level.
He only knew that yōkai of this caliber seemed to be referred to by lesser yōkai as Generals, and could also be called Great Yōkai.
Although he didn’t fully grasp the details, Hikaru found the title of Great Yōkai easy enough to understand.
After all, based on his observations of Quality Transformation, the ultimate limit of Perfect Mass allowed a yōkai—depending on its own choices—to achieve a form infinitely close to that of a human.
Appearing human—wasn’t that the fundamental characteristic of a Great Yōkai in countless fantasy works?
And the final stage beyond that was called Form Transformation.
Hikaru theorized that the foundation of Form Transformation was a complete shapeshift into a higher-tier form.
It wouldn’t be a simple disguise or mere resemblance; it would mean existing simultaneously as a yōkai and as that new form, almost to the extent of possessing two distinct bodies, or even being capable of siring offspring that were purely non-yōkai.
Yōkai capable of completing Form Transformation were often hailed as Yōkai Kings.
They were entities capable of openly establishing their own territories, ruling over a province or a country, and founding a yōkai nation.
Thus, the Four Transformations and Twenty-Four Stages: Body Transformation covered stages one through six, Quality Transformation covered stages seven through twelve, and Aura Transformation covered stages thirteen through eighteen…
From weak to strong, though the details varied, most yōkai followed this fundamental rule.
Even if some powerful yōkai didn’t show outward signs, it was highly likely their internal structures were enhanced, boosting their pure stats in strength and speed.
As for Hikaru himself—
He was currently in the initial phase of Body Transformation.
The fifth stage.
Only the fifth stage.
Each stage corresponded to a trait granted by a weapon he had successfully conquered.
The first stage was the [Tough Body Transformation] brought by his initial katana, making his skin as tough as iron.
The second stage was the [Sharp Eyes Transformation] from a dagger, drastically improving his dynamic vision.
The third stage was the [Archer Arms Transformation] from a broken bow, doubling his upper body strength.
The fourth stage was the [Spear Waist Transformation] from a spear, making his waist and abdomen absurdly flexible.
The fifth stage was the [Shield Bones Transformation] from a shield, increasing his bone density and greatly enhancing his resistance to blows.
Five weapons, five mutations.
Maxing out the affinity of each weapon allowed him to integrate its ability into himself, simultaneously completing one stage of transformation.
This was likely the core function of his system.
Other yōkai had to spend countless years and endure grueling trials to evolve, surviving by the skin of their teeth.
He only needed to grind affinity.
Simple and efficient.
Traceable and predictable.
More importantly, he could independently choose what kind of transformation he wanted.
Unlike other yōkai, who had to rely on luck and mutate randomly.
“Here comes another one!” he muttered.
A massive Centipede Spirit charged out from the flank.
Its body was a full twenty feet long, and the carapace on its back gleamed with a metallic luster.
This Centipede Spirit was at least at the fourth stage.
An elite among those in the Body Transformation phase.
But that was all it was.
Hikaru sidestepped to dodge the Centipede Spirit’s headbutt, dragging his blade across its underbelly.
The carapace was too hard; it didn’t cut through.
But blood still splattered.
Through those beads of blood, Hikaru clearly saw the seams in the Centipede Spirit’s armor.
Between the seventh and eighth segments, there was a microscopic crack.
He pushed off the ground, flashing to the Centipede Spirit’s side once more.
He thrust the tip of his sword into the crack.
And twisted.
The Centipede Spirit’s agonized shriek echoed through the woods.
Hikaru didn’t give it a chance to struggle.
He dragged the blade forward along the seam, directly disemboweling the giant yōkai.
Its innards spilled all over the ground.
A fourth-stage yōkai directly yielded three points of affinity.
Sure enough, the higher the quality of the prey, the greater the reward.
Hikaru licked his lips and continued to push forward.
The yōkai horde began to waver.
The smugness on the face of the Green-Skin Demon boss hiding in the back had vanished, replaced by sheer terror.
“What is going on?!” it shrieked.
“He’s just a Ghost Samurai!
A low-level undead yōkai!
How can he be this strong?!”
No one answered it.
Because anyone who could answer was already dead.
Hikaru’s sword never stopped moving.
One strike, one life.
Occasionally two strikes.
But he never needed a third.
The numbers on his interface constantly ticked upward.
Muramasa’s blade had turned from black to a deep purple.
The hamon pattern writhed like a living creature, emitting a satisfied hum with every kill.
It was happy.
Very happy.
“Your appetite is getting bigger and bigger,” Hikaru grumbled, though his hands never stopped moving.
Another Green-Skin Demon fell.
Hikaru looked at the new ability on his interface, his eyes lighting up.
A 30% boost to all stats.
Although it had side effects, it was a trump card for saving his life in critical moments.
“Not bad,” he said to the sword in his hand.
“Keep up the good work.
When I get stronger, I’ll find you a true high-level yōkai for the main course.”
There were fewer than fifty yōkai left on the battlefield.
The Green-Skin Demon boss finally broke and turned to flee.
“Retreat!
Everyone, retreat!”
The remaining small fry scattered and fled, as if granted a pardon.
Hikaru did not pursue them.
He had killed enough.
If he kept killing, his stamina would be severely overdrawn.
If he ran into another yōkai horde on the road, he would be in trouble.
He stood amidst the mountain of corpses and sea of blood, watching the retreating shadows of the yōkai.
The moonlight spilled down, stretching his shadow long across the ground.
His damaged gusoku armor was stained with blood of various colors, and the black tachi was still trembling slightly, as if savoring its recent feast.
‘One hundred and fifty-three.’
Hikaru silently tallied his spoils.
Affinity had risen from 28 to 50, an increase of 22 points.
It took an average of seven kills to gain a single point.
As expected, the cost-effectiveness of small fry was far too low.
He sheathed his sword.
*Click.*
The sound of the scabbard locking against the handguard echoed in the silence.
‘Time to go.’
He looked up toward the distant mountains.
There, a shrine maiden named Kikyō was waiting for him.
‘No.’
‘It’s the Jewel of Four Souls waiting to be delivered.’
‘And incidentally…
waiting to have its affinity unlocked.’