Another day passed, and the master and disciple, following the map and the occasional sporadic information from the Kasugai Crow, tracked their target to a hilly area with somewhat unusual soil.
The mud here had an unnatural dark red color and felt somewhat sticky and soft when stepped on.
"Teacher, the smell... it's stronger, and very muddled, like... it's melted into the earth."
Tanjirou's nostrils flared, and his brows were tightly furrowed.
His hand remained on his sword hilt, as he vigilantly scanned the seemingly calm ground around him.
Cheng Mo nodded slightly.
What he sensed was even clearer.
A chilling energy, like a spiderweb, was spread throughout the soil beneath his feet, connected to a central source.
"He's here," he murmured.
No sooner had he spoken than the mud in an open space ahead violently churned!
It was a young man with a ferocious expression, constantly exuding viscous dark red mud that merged with the ground around him.
"Disgusting demon slayers... walking right into my trap..."
"It's a demon!" Tanjirou immediately adopted a combat stance, his katana held horizontally in front of him, instantly activating his Full Focus Breathing.
The Swamp Demon roared, plunging both arms into the ground!
In an instant, the ground beneath Tanjirou became like quicksand, and two giant hands made of viscous mud suddenly shot out, grabbing at his ankles!
"It's a Blood Demon Art!"
Tanjirou exclaimed, leaping backward with all his might, narrowly avoiding the attack.
But the mud hands seemed to have a life of their own; missing their target, they immediately dispersed.
The mud transformed into several mud snakes, coiling around Tanjirou from different angles. They weren't fast, but they were extremely tricky, blocking his movement space.
Tanjirou swung his sword, his katana able to cut through the mud flow.
However, the severed parts quickly merged back into the swampy ground beneath his feet, re-coalescing as if endlessly.
He was trapped in a situation of passive dodging and parrying. Although these mud attacks weren't very powerful, only causing pain and hindrance when they hit, they couldn't inflict fatal wounds.
But they greatly drained his stamina, preventing him from getting close.
Cheng Mo stood outside the battle, observing calmly.
His gaze penetrated the demon's ugly exterior, directly locking onto the energy circulation within its body.
In the Eye of Truth's vision, whenever the demon used its Blood Demon Art, the core evil energy within its body would rapidly construct an extremely complex and intricate energy structure.
This structure, like a tiny magic circle, formed in an instant.
Then, the demon's flesh and blood energy would be transformed through this "magic circle core" and injected into the ground beneath its feet, thereby triggering the supernatural effect of manipulating mud.
"Energy transformed and outputted through a specific structure? Not simply relying on bloodline instinct?"
Cheng Mo's mind raced with analysis.
"This is more like... a surgical procedure (technique)? A special energy application technique based on the demon's life form?"
This discovery slightly shook his mind.
He had previously been practicing the attack variations of Lightning Release Chakra, always trying to understand and control it with a modern scientific energy perspective, and progress had been slow.
But the demon's Blood Demon Art before him opened another door for him—
A method of energy construction and release that leaned more towards the "mystical side"!
He subconsciously began to imitate.
He concentrated his mind, mobilizing the Lightning Release Chakra within his body, which also did not belong to this world.
He attempted to construct a rudimentary energy structure in his palm, similar to the one within the demon's body but with entirely different attributes.
Then, he infused it with the violent and swift characteristics of Lightning Release.
This process was extremely difficult, demanding a high level of mental power and energy control.
But Cheng Mo possessed the microscopic insight of the Eye of Truth and the super control brought by the Myriad Realms Physique.
After several failed attempts, an extremely unstable energy structure, flickering with tiny electric sparks, finally vaguely formed in his palm!
He immediately injected a tiny stream of Lightning Release Chakra into it, and then, mimicking the demon's method, directed it towards the ground—
"Crack!"
A faint crackling sound!
An energy construct, entirely made of azure lightning, like a thorny vine, suddenly shot out from the ground beneath the Swamp Demon's feet!
Although its form was still crude and its duration extremely short, it precisely entangled the demon's legs, and the intense numbness instantly stiffened its movements!
"What?!"
The Swamp Demon let out a shriek of horror, completely unable to comprehend what had happened!
Why was lightning attacking it from underground?
This was not its ability at all!
Tanjirou was also stunned, staring at the lightning vine that suddenly appeared and then instantly vanished, his mind blank.
But his battle instincts made him seize this fleeting opportunity.
"Full Focus!"
He roared, squeezing out all his strength, breaking through the obstruction of the mud flow. His katana, carrying a decisive momentum, fiercely slashed across the demon's neck, which was exposed due to its rigidity!
Splish!
The head flew off!
Only then did Tanjirou suddenly turn back to look at his teacher, his eyes filled with disbelief: "Te-teacher, what was that just now... did you... did you learn its Blood Demon Art?!"
Cheng Mo stepped forward, tiny electric arcs dancing on his fingertips, accurately touching the severed head to completely end its existence. At the same time, his other hand had already produced a special sampling tube, quickly collecting some of the dissipating demon body tissue.
After doing all this, he looked at his stunned disciple, his tone still calm, as if he had done something insignificant:
"Not learned, just observed the way its energy operates, imitated the structure a bit, and tried it with my own power. The effect... is acceptable."
Tanjirou's mouth hung open, speechless for a long time.
Observe? Imitate? Try?
It's that simple?!
His teacher could actually imitate a demon's Blood Demon Art just by watching it once?!
This was simply miraculous!
His reverence for his teacher instantly rose to a whole new level.
That night, the two camped under a dry rock formation, far from the low-lying area.
Tanjirou diligently practiced his stance training nearby, striving to digest the day's combat experience and his new insights into the Breathing Technique.
Cheng Mo, however, uncharacteristically did not immediately enter cultivation.
He sat by the campfire, watching the flickering flames, lost in thought.
Today's unexpected gain made him realize that his previous thinking might have been somewhat limited.
He had been trying to understand Chakra, an extraordinary power, solely through the framework of modern science, working in isolation, and progress had been slow.
But the "Blood Demon Art" of this world, although its energy source was evil, its operational principle—
Generating real-world effects by constructing specific energy structures—provided him with a completely new line of thought.
"Energy structures... techniques... In the original work, the changes in Chakra's form and nature also require similar 'blueprints' or 'seals' to guide them..."
He felt as if he had touched upon a threshold.