Mount Momoyama.
The waterfall roared, and mist filled the air.
"Hinokami Kagura: Waltz!"
The rock under Tanjirou's feet gave a slight tremor, and he shot out like an arrow from a bowstring!
His nichirin blade carved a scorching arc, bringing with it a searing heat.
Cheng Mo shifted slightly, casually deflecting with his jingzhe, half-unsheathed.
He precisely struck Tanjirou's tsuba, diverting his force.
But Tanjirou changed his move extremely quickly, using the rotational force to sharply thrust his blade upwards.
"Azure Heaven!"
The scorching, upward-rotating slash caused the surrounding mist to vaporize, as if it would cleave the very sky.
Cheng Mo's wrist flicked, and jingzhe again struck first despite being launched later, blocking the attack.
The dull thud of the collision was swallowed by the roar of the waterfall.
Tanjirou didn't stop; the moment he landed, he pushed off, his figure like lightning, his blade's gleam transforming into a series of dazzling, lingering images of the scorching sun.
"Scorching Crimson Mirror!"
Continuous slashes came from various tricky angles, a perfect combination of heat and speed, blocking all of Cheng Mo's escape routes.
Cheng Mo's figure left several blurry afterimages in place.
Jingzhe parried or blocked, each time perfectly intercepting Tanjirou's attacks, emitting rapid "clangs."
Just as the assault briefly slowed, a glint flashed in Tanjirou's eyes.
All his power suddenly compressed, then exploded!
"Waltz... Flash!"
He seemed to transform into a crimson-gold bolt of lightning, his speed suddenly reaching a new level.
The tip of his blade thrust directly at Cheng Mo's centerline!
This strike, a thrust that incorporated the ultimate speed of Thunder Breathing, was faster than his previous limits.
Even the air shrieked as it was torn apart!
Cheng Mo's eyebrow twitched slightly, seemingly surprised.
He finally took a step back, and at the same time, his jingzhe precisely extended diagonally forward.
Clang!
With a crisp, resonant sound, Tanjirou's strike, which concentrated all his power and speed, was firmly held by the tip of jingzhe, unable to advance another inch.
The immense recoil made Tanjirou's hands tingle, and he stumbled back a few steps.
Almost simultaneously, a golden bolt of lightning silently stabbed from the side!
It was so fast that the blade itself was almost invisible; only the sharp sound of it tearing through the air revealed its power.
"Thunder Breathing, First Form: Thunderclap and Flash!"
Zenitsu's eyes were tightly shut, tears still on his face.
Yet his body was like a taut bowstring, unleashing a ferocious strike far beyond his usual timid demeanor.
Cheng Mo didn't even turn his head; he flicked the wrist of the hand holding the scabbard.
While shaking off Tanjirou, his other hand casually swept backward, the scabbard precisely striking the side of Zenitsu's blade.
Clang!
Zenitsu felt an irresistible, skillful force, and his long sword nearly flew from his grasp.
He stumbled out, screaming in terror: "Ahhh! I'm going to die! I'm going to die!"
Cheng Mo stood with his blade sheathed, his breathing steady.
Tanjirou leaned on his sword, his chest heaving violently, sweat mixed with waterfall mist continuously dripping from his chin.
He looked at Cheng Mo, whose clothes weren't even ruffled, his eyes full of admiration and helplessness: "Teacher... you are so amazing... I thought I had made great progress... You didn't use your lightning power, didn't even unleash a sword form... yet you could easily block it..."
Cheng Mo looked at him, his tone calm: "Because my physical capabilities are far superior to yours. No matter how exquisite your moves are, they are too slow in my eyes."
He paused, then added: "There's a saying in my homeland: 'Among all martial arts, none is unbreakable, except for speed.' Moves and techniques only work when the combatants' strengths are relatively similar."
"This is also why I had you build a strong foundation, temper your physique and strength from the beginning. Your foundation determines the limits of your speed and strength."
Tanjirou was stunned, muttering the words "only speed is unbreakable" to himself.
He felt that this simple, direct phrase contained a profoundly deep truth, instantly resolving many of his confusions about training.
The teacher's words were always so intuitive yet profound.
He nodded repeatedly, his eyes shining, as if he had grasped something new.
Cheng Mo's gaze turned to Zenitsu, who had just climbed up from the base of the cliff.
He had a large bump on his head and teary eyes.
Kuwajima Jigorō, who had been watching from the shore, stroked his beard and laughed heartily, though his eyes were a little moist.
He looked at the two rapidly progressing youths: "Hahaha! Good, both good! The future of my Thunder Breathing lineage is bright; with these children, this old man can die in peace! Hahaha!"
The old man laughed heartily, filled with relief and pride.
Cheng Mo turned to Kuwajima Jigorō, his expression a little more serious: "Teacher, I will be traveling for a while to attend to some personal matters."
As soon as he said this, Tanjirou and Zenitsu immediately showed anxious and reluctant expressions.
"Teacher, you're leaving?"
Tanjirou quickly stepped forward.
"Are you going for a long time? Is it dangerous? I... can I go with you? I can help now!"
Zenitsu also looked at Cheng Mo nervously.
Cheng Mo raised a hand, stopping their words: "There's no need."
"Your arduous training has reached a bottleneck; practicing in isolation will ultimately make breakthroughs difficult. From now on, actual combat is the best teacher."
His gaze swept over Tanjirou and Zenitsu: "Go participate in the Final Selection at Mount Fujikasane. Become official swordsmen, and let real combat test the results of your training."
Upon hearing this, Tanjirou's eyes instantly became incredibly resolute.
He gripped the long sword in his hand tightly and nodded heavily: "Yes! Teacher, I will certainly not let down your teachings; I will become a qualified Demon Slayer Corps swordsman! And then, I will slay more demons!"
Zenitsu, however, had an expression as if the sky had fallen, and tears began to stream down his face again:
"Wahhh... The Final Selection... people really die there! I heard it's full of demons! I'll die, I'll definitely die... Noooo..."
But after trembling for a long time, looking at Cheng Mo's calm gaze, he finally cried out and nodded, "But... but... I understand! I'll go, boo hoo hoo... If I die, Big Brother, remember to burn paper offerings for me..."
Cheng Mo said no more.
He turned to Kuwajima Jigorō and bowed solemnly.
The old man put away his smile, patted his shoulder, everything understood without words.
Then, Cheng Mo raised his hands and patted Tanjirou's and Zenitsu's shoulders respectively.
The movements were light, yet carried a heavy expectation.
Without further farewell words, Cheng Mo turned.
In a few leaps and bounds, his figure disappeared into the lush mountain forest.
Behind him, the waterfall still roared, mingled with Tanjirou's forceful shout of "Teacher, take care!"