Raiden's eyes narrowed as he noticed that Muzan still had not returned to his true form after taking that strike. A faint twitch crossed his brow, and a cold light flickered in his gaze.
Muzan dared to regenerate right in front of him. It was as if he did not take Raiden seriously at all.
Raiden tightened his grip on his Nichirin blade, preparing to strike again and force Muzan to understand his situation.
Just as he was about to move, Muzan suddenly spoke. His voice carried restrained anger, yet there was an odd softness beneath it.
"Wait, Raiden."
Raiden paused slightly, his brows drawing together. "Hm?"
Muzan continued, his tone strangely captivating, almost hypnotic.
"Awakening the Demon Slayer Mark means you will not live past twenty-five. Don't you think that is a waste?"
Raiden sensed the subtle manipulation in Muzan's voice but chose not to expose it. His fingers tightened around his sword, ready to attack at any moment.
"A waste? Maybe a little."
Seeing this, Muzan leaned further into his act, buying time.
"Become a demon. With your talent, you should not be bound by such a fragile lifespan. If you become a demon, that limitation disappears."
Inwardly, Muzan calculated every second. If he could stall just a bit longer, he could suppress Tamayo's poison enough to escape.
As for actually turning Raiden into a demon, that was never his intention.
Raiden was already dangerously close to his level. Muzan had no interest in creating another enemy like himself. This was nothing more than deception.
Raiden's lips curled into a faint, mocking smile. He was about to call Muzan out, but then a different thought crossed his mind.
Why not take advantage of this?
If he killed Muzan now, everything would return to normal. But if he could make Muzan his "friend" first, that might be far more useful.
"Then if I become a demon, what would our relationship be?"
Raiden spoke as if he were genuinely considering it.
Muzan was momentarily caught off guard.
"A relationship?"
Partners? Allies? Friends?
The word lingered in his mind, and he recalled their first meeting. Raiden had tried to befriend him back then as well.
Muzan hid his thoughts and pretended to consider the question while quietly observing his own recovery.
Just two more minutes.
That was all he needed.
Finally, he looked at Raiden and spoke carefully.
"A friendship?"
Raiden's grin widened.
[Ding]
[Friend request from Kibutsuji Muzan detected. Accept?]
[Yes]
[Friendship level: Initial Acquaintance]
[Reward obtained: Demon King's Body]
[Fuse ability now?]
[No]
Raiden's gaze swept over the system panel, satisfaction clear in his expression.
Whatever this ability was, as long as it was something usable, it would be valuable.
Muzan, seeing Raiden's pleased reaction, let out a quiet breath of relief.
So easy.
This fool was actually happy after being tricked.
He would regret it soon enough.
Nearby, the others grew tense.
If Raiden truly became a demon, his strength would make him an absolute nightmare.
Shinazugawa frowned, unease creeping into his expression. If Raiden loved making friends so much, did he really have to choose a demon at a time like this?
Inosuke pointed at Muzan. "So the big meatball is dying, right?"
Tanjiro and Zenitsu nodded silently.
Unlike the others, the three of them understood exactly what was happening.
Except for Tamayo and Yushiro, any demon who became Raiden's "friend" never survived.
They were not worried about Raiden turning into a demon.
They were worried for Muzan.
If Raiden called you a friend, it usually meant one thing.
You were about to get cut down.
"To become a demon, you need..."
Muzan began to explain, but before he could finish, a sharp flash of steel cut through the air.
A clean strike landed.
The blow carried no breathing technique, yet it completely destroyed all the recovery Muzan had managed during the delay.
Pain surged through his body, but Muzan did not react with anger at first.
He looked confused.
Raiden had looked genuinely pleased just moments ago.
They had agreed on friendship.
So why was he still attacking?
"...You?"
Muzan stared at him, disbelief evident.
Raiden smiled lightly, almost amused.
"Oh, this is how I treat all my friends. Doma and Akaza are my friends too."
Muzan fell silent.
In that moment, realization hit him.
He had been played.
Raiden never intended to become a demon. He had been toying with him from the start.
Any hope of stalling vanished.
Muzan's body twisted violently. The mass of flesh writhed like living creatures, expanding and contracting in grotesque motion.
Muscles and bones ground together with a sickening sound before compressing into a human shape once more.
His middle-aged form reappeared, but it was far from elegant.
His upper body was covered in twisted, thorn-like flesh, writhing like vines wrapped tightly around him. The air filled with a foul, metallic stench.
The monstrous growths pulsed and shifted, as if alive.
Muzan's expression darkened.
"Since you insist on this path, I will end you myself."
"Sure."
Raiden's smile deepened, calm and confident.
[Fuse Demon King's Body now?]
[Yes]