The golden-haired young man was teleported to a platform. He stood steadily on the platform, and a familiar figure stood in the distance.
Zenitsu Agatsuma and his senior disciple, Kaigaku, who had become a demon!
Zenitsu's gaze was terrifyingly cold. It was this person in front of him who had groveled before the demons and chosen to betray them and become a demon, causing their master, Jigoro Kuwajima, to commit seppuku in apology.
Kaigaku, who had turned around, no longer looked like the person Zenitsu remembered. He had grown fangs, his ears were pointed, his skin was pale, the whites of his eyes were black, there were black tiger-stripe demon markings on his face, his nails were long and black, and he wore a black kimono tied with a blue sash at his waist.
"I heard the old man died? That's much quieter."
Kaigaku looked at the golden-haired young man in front of him with disdain, not even caring about him.
Just after the first sentence, Zenitsu's forehead was already bulging with veins.
"But you're still as poor as ever. Long time no see, Zenitsu."
"You haven't changed at all! Small, shabby, and still weak. Oh, have you learned any moves other than the First Form?"
Kaigaku, who was talking nonstop, flashed and appeared directly in front of Zenitsu.
"Then have you learned to use the First Form?"
Zenitsu shot back rudely to Kaigaku. The veins on Kaigaku's forehead also bulged.
"Don't compare me to you, you trash."
Zenitsu's lips curled into a cold smile, and he said without hesitation.
"Don't you know, Kaigaku, Muzan Kibutsuji is about to die."
"Once Muzan dies, all demons will die, and you..."
"You, who are clinging to life, wouldn't have thought, would you, that your pathetic begging for mercy will let you live only a few more days more."
Kaigaku's face finally changed. He shot back to Zenitsu.
"Muzan-sama won't die. Instead, it's you, the Demon Slayer Corps, who will surely be wiped out."
Zenitsu, who was merely sneering at his ugly face, no longer responded. He slowly drew his golden Nichirin Sword.
"Right, after all, you won't live to see the day Muzan Kibutsuji dies."
"You're still so annoying!"
Kaigaku also drew his own blade. This blade was identical to the Nichirin Sword he had once used, but this blade was forged from his flesh and blood. The blade was dark gold with lightning-shaped blade patterns, the hilt was also dark gold, the scabbard was black, and the guard was white with a triangular pattern on it.
The master and disciple said nothing more. Their two blades instantly clashed. Zenitsu felt a surge of power from the blade and took a step back with his right foot. After becoming a demon, Kaigaku's basic strength had greatly increased!
"Is that all you've got for your big talk?"
Blade after blade, Kaigaku's blade swung continuously, while Zenitsu blocked with his blade. The master and disciple had already exchanged dozens of blows in just a few breaths, and the blade light covered a large circle around them.
Kaigaku's strength was clearly stronger, but no matter how much he increased his strength and speed, his attacking blade would still be blocked by Zenitsu, which made him a little anxious.
Finding a chance to create distance, black lightning slowly appeared on Kaigaku's blade, and the crackling sound of electricity filled the air.
This was Kaigaku's Blood Demon Art. Its ability was to transform the golden lightning produced by the Breathing Style into special black lightning, which would cause continuous damage after striking an enemy. The slashes could tear the opponent's skin and form lightning-shaped wounds, while the extremely high heat carried by the lightning would continuously spread within the body along the wounds, bringing the opponent the pain of their flesh being burned.
Zenitsu didn't know the effect of the black lightning, but he could vaguely sense that once he was struck, things would become very troublesome.
"Thunder Breathing—Fourth Form: Distant Thunder!"
Kaigaku transformed into a black lightning bolt and rushed towards Zenitsu. But as Kaigaku launched his attack, Zenitsu's Thunderclap and Flash had already activated, transforming into a golden lightning bolt to avoid the attack.
"Distant Thunder's speed can't compare to Thunderclap and Flash."
Zenitsu couldn't help but mock him, as Kaigaku couldn't learn the First Form, Thunderclap and Flash.
"Shut up!"
A massive burst of lightning-shaped slashes erupted around Kaigaku's body, surging outwards.
"Thunder Breathing—Sixth Form: Rumble and Flash!"
High-density black slashes either had to be blocked by defensive moves similar to spinning, or avoided by creating distance to find openings.
Zenitsu naturally chose the second option, shifting his feet and quickly jumping backward. Seeing Zenitsu retreat, Kaigaku grinned.
Faster than lightning, Kaigaku changed his sword technique.
"Thunder Breathing—Fifth Form: Heat Lightning!"
A huge black lightning bolt shot directly towards Zenitsu. Zenitsu, who had just jumped, saw a pitch-black current shoot out from below at an impossible speed to see.
Boom!
Thick smoke billowed, and dust flew. When the wind cleared, Zenitsu stood unharmed in his original spot.
"How is that possible!"
Kaigaku was shocked.
That's right, under normal circumstances, a person floating in the air would not be able to dodge such a high-speed attack. However, Zenitsu was not an ordinary person. In his eyes, the world was slow and Transparent.
He was one of only two people who learned the Transparent World during Seiichi's special training.
Zenitsu recalled the special training period.
Seiichi watched Zenitsu repeatedly try to use the Red Nichirin Sword. The blade's faint redness was already its limit and could not be used as a normal fighting method.
"Actually, there's no need to worry about the Red Nichirin Sword, Zenitsu."
Seiichi patted Zenitsu's shoulder. He could tell that the young man was currently overthinking things. After all, he had just lost a loved one, and sad emotions filled his heart, and the anger of wanting revenge would make people try anything.
Seiichi didn't take this matter seriously at the time, because with his existence, the Upper Moons were almost impossible to appear again, and Kaigaku was even less likely to encounter Kokushibo.
In fact, Kaigaku did not encounter Kokushibo, but he encountered Muzan Kibutsuji.
Sitting beside Zenitsu, Seiichi spoke as if in casual conversation.
"Do you know what you need most when you're moving at high speed?"
"Stamina?"
Zenitsu thought for a while before answering. He had once fought Daki and realized the importance of stamina.
"Not really. A senior named Kakashi once said that when you move at high speed, dynamic vision is the most important thing."
Zenitsu was stunned, somewhat understanding.
"When you have both speed and precise control, then you are unbeatable. So, fully experience the Transparent World."
The words seemed to still echo in his ears.
Zenitsu looked at his former senior disciple in front of him, filled with killing intent yet also huge sadness. No matter what, he had once spent a period of his life with him.
He had indeed once looked up to him as a role model, wanting the day he could fight alongside him.
"I'm sorry, Kaigaku..."
Golden electrical light erupted from Zenitsu's entire body, and his breathing was accompanied by continuous thunder.
"Is it Thunderclap and Flash again? That's enough, I've had enough of your..."
At a speed impossible for demon eyes to see, Zenitsu performed a high-speed dashing slash, its path as dazzling as a flying thunder dragon, his eyes clear and bright.
"Thunder Breathing—Seventh Form: Honoikazuchi!"
Too fast! At this speed, Zenitsu, who originally couldn't adjust his movements, could now continuously adjust with the help of the Transparent World, aiming directly for the neck, ensuring a single fatal blow!
Whoosh!
The electric light flashed by. Kaigaku didn't know what had happened, only feeling a sharp pain in his neck.
"You..."
Zenitsu was already behind him.
Bang! His head hit the ground with a dull thud.
Tears welled up in Zenitsu's eyes.
"Grandpa, I'm sorry..."