"Alright, this should suffice."
In a dark secret room, Lynn tossed Gyutaro back onto the ground and turned to look behind him.
"With the Ubuyashiki Residence as bait, Muzan won't launch a second wave of attacks immediately."
"That's great, I can finally rest a bit."
Uzui Tengen breathed a sigh of relief.
Among those present, he could be considered the most exhausted.
First, he fought a prolonged battle against three Lower Rank Demons all night, and after being rescued by Lynn, he rushed non-stop to the Rengoku Residence to deliver a message, finally engaging in a fierce battle with the two Upper Rank Demons Lynn attracted.
If he hadn't managed to rest for a few hours at the Rengoku Residence in between, he probably would have died from exhaustion by now.
"You all go up and rest for a while."
Lynn's voice sounded again.
After signaling Uzui Tengen and the others to go up first, he looked towards the middle-aged man standing in the corner.
The man's appearance bore a nine-tenths resemblance to Rengoku Kyojuro, but his temperament was completely different.
If Rengoku Kyojuro was the rising sun, full of vitality and passion,
then the man before him was the setting sun, and even though the afterglow remained, the signs of old age could not be concealed.
"Mr. Rengoku Shinjuro, after witnessing the successive fall of the Upper Ranks, what are your thoughts?"
"You have awakened a slumbering monster."
"Monster? Who are you referring to?"
"The Progenitor of Demons, Kibutsuji Muzan."
Rengoku Shinjuro sighed, feeling no joy in this victory.
As a descendant of the first user of the Flame Breathing Technique, Rengoku Shinjuro knew many secret histories.
"The Upper Rank Demons are indeed terrifying, but they are still far inferior compared to Kibutsuji Muzan."
"If there is a chasm between the Upper Ranks and the Lower Ranks, then a chasm exists between Kibutsuji Muzan and the Upper Rank Demons as well."
"Having experienced the power of the Upper Two, do you truly believe that you and the others can defeat a monster of a higher tier?"
"Setting aside the question of whether we can win or not, what concerns me more right now is your mindset."
Looking at the man before him, who was wallowing in self-pity and completely devoid of fighting spirit, Lynn asked.
"As a Hashira of the Demon Slayer Corps, do you intend to retreat at this juncture?"
"...What if I say yes?"
"Then help me one more time before you retire. You can watch over Gyutaro tonight."
Seeing Rengoku Shinjuro adopting a completely laissez-faire attitude, Lynn did not press further with persuasion.
In reality, Rengoku Shinjuro owed the Demon Slayer Corps nothing. His decision to join was influenced by his father, and he had made many contributions to the Demon Slayer Corps before giving up.
Lynn had brought up these matters purely because the timing was right, hoping that defeating an Upper Rank Demon might reignite his fighting spirit.
Since that failed, there was no need to say more.
After bidding farewell to Rengoku Shinjuro, Lynn left the underground secret room and returned to the surface.
At the entrance to the secret room, Uzui Tengen and the others, who had stepped out first, had not gone far, stopping tacitly to wait for Lynn.
And besides Uzui Tengen and the others, there was also a figure clad in fiery red standing at the entrance of the secret room.
"Lynn! You're here!"
Rengoku Kyojuro, who had been pacing near the entrance of the secret room, walked up with a look of curiosity.
"I heard the other Hashira saying you were chatting with my father downstairs. What did you talk about?"
"The matter of surrounding and eliminating Muzan."
"What did my father say?"
"He lacked fighting spirit."
Lynn replied tactfully.
"This..."
Rengoku Kyojuro fell silent.
He was very clear about his father's condition.
Lynn's words essentially meant that Rengoku Shinjuro had withdrawn from the upcoming operation.
"I'm sorry."
"You don't need to apologize. The one who is afraid is your father, not you."
"No, I apologize because my strength is insufficient. There is nothing I can do right now."
Rengoku Kyojuro clenched his fists, a rare look of unwillingness appearing on his face.
Because he had practiced Breathing Techniques and swordsmanship since he was young, Rengoku Kyojuro's starting point was very high; he had even mastered Total Concentration Breathing Constant.
If he had been given a few more years to develop, he would definitely have been qualified to become a Hashira and join Lynn and the others in besieging Kibutsuji Muzan.
But reality was cruel; the decisive battle between the Demon Slayer Corps and Muzan would commence in ten days.
With his current strength, he would absolutely not be able to join the main battlefield in ten days, only able to assist with minor tasks.
"If only there were a way to become stronger quickly. I also want to fight alongside you."
"There is a way to quickly become stronger."
"Hm?"
Listening to Lynn's voice, Rengoku Kyojuro, who had been sighing inwardly, froze. The people standing nearby, including Uzui Tengen, also froze.
Although they had defeated Doma through cooperation, Uzui Tengen and the others had also realized the gap between themselves and the Upper Rank Demons through that battle.
If the Upper Two were like that, the Upper One and Kibutsuji Muzan would only be more terrifying.
In order to become stronger and not drag everyone down, Uzui Tengen and the others all looked towards Lynn.
"Lynn, is there really such a method?"
"There is. Just activate the Mark, and your physical fitness will instantly jump up a level."
"The Mark?"
Himejima Gyomei tried hard to recall but found that he had no impression of this term.
"What is the Mark?"
Tomioka Giyu, who also had no impression, asked.
"Simply put, the Mark is a special physique possessed by Tsugikuni Yoriichi, the creator of the Sun Breathing Technique."
"Influenced by Tsugikuni Yoriichi, the Sun Breathing Technique and its derivative Breathing Techniques can, under the right conditions, allow the user to partially replicate the Mark physique, elevating their physical fitness."
"The Mark, the creator of the Sun Breathing Technique... Hmm, it sounds quite formidable!"
After listening to Lynn's explanation, Rengoku Shinjuro concluded after some thought.
"In short, if I can activate the Mark, I will possess the strength of a Hashira, right?"
"That depends on your definition of a Hashira."
"Killing a Lower Rank is no problem, but the Upper Ranks might be a bit difficult; at most, I can only provide support."
"That's fine! That's enough!"
Rengoku Shinjuro was very satisfied with this. "Lynn, how can I activate the Mark?"
"I cannot say for now."
"Eh?"
Rengoku Shinjuro paused.
"Why can't you say?"
Uzui Tengen, standing nearby, frowned, vaguely realizing something.
"Could it be... that activating the Mark has some side effects?"
"Yes, I mentioned it before. The Mark is Tsugikuni Yoriichi's special physique."
"If one forcefully activates the Mark to become stronger through a Breathing Technique, it will place a severe load on the body."
Lynn raised both hands, holding up two fingers on his left hand and five fingers on his right hand.
"To put it in terms you can understand, anyone who activates the Mark will not live past the age of twenty-five."
"..."
As Lynn's words fell, the atmosphere in the room instantly became heavy.
Everyone looked at each other, finally understanding why Lynn had kept silent about the Mark before.
A moment later, it was Kocho Kanae who broke the silence first.
"Lynn, have you activated the Mark?"
"I haven't. If I were to activate the Mark, you all would also be affected."
"What do you mean?"
"After activating the Mark, the Mark holder will influence other people nearby who use Breathing Techniques, making it easier for them to activate the Mark."
"I see. Then I misunderstood."
Kocho Kanae nodded thoughtfully.
She had originally thought that Lynn's rapid rise in just a few months was because he had activated the Mark.
But now it seemed Lynn was still the same Lynn, an unreasonably talented monster.
"Please tell me the method to activate the Mark."
Just then, Tomioka Giyu's voice sounded again.
The usually taciturn man was unusually talkative at this moment.
"I'm not afraid of death. Even if it shortens my lifespan, it doesn't matter, as long as I can kill Kibutsuji Muzan."
"If you're worried that me activating the Demon Slayer Mark will affect you, I'll keep my distance..."
"Stop! You shut up first!"
Tomioka Giyu's rare moment of initiative was met with Lynn's merciless interruption.
"I hadn't even finished speaking. Actually, I know a method that can negate the side effects of the Demon Slayer Mark, allowing you to activate it and still live a long life."
"Then why didn't you say so earlier!"
Uzui Tengen couldn't help but complain.
"Unfortunately, I couldn't have said that earlier either."
Lynn shrugged. "Just like the side effects of the Demon Slayer Mark, this method to cancel the side effects involves a taboo. I need to negotiate with Ubuyashiki Kagaya before deciding whether to disclose it."
"..."
Are you pulling a nested doll routine here?
Uzui Tengen twitched at the corner of his eye, speechless at Lynn's cryptic behavior.
The side effects of the Demon Slayer Mark are too serious to mention → There's a method to cancel the side effects → The method to cancel the side effects involves a taboo and can't be mentioned.
After Lynn's series of maneuvers, apart from revealing the existence of the Demon Slayer Mark (which piqued their curiosity), it was essentially saying nothing at all.
"You're not going to say next that you can't return to the Demon Slayer Corps due to some unforeseen circumstances, are you?"
"Not at all. I plan to rest here tonight and return to the Demon Slayer Corps tomorrow morning."
"Time is limited. It's better to set off as soon as possible." Tomioka Giyu stepped forward. "If you're tired, I can carry you back."
"Scram! I said sleep, so sleep. Don't add unnecessary drama!" Lynn rolled his eyes.
Of course, he wasn't feeling tired.
In fact, the strain he showed during the battle was all an act.
He was not only deceiving Kibutsuji Muzan but also Ubuyashiki Kagaya.
To obtain the demon king potion, he had to make Ubuyashiki Kagaya feel a certain amount of pressure, prompting a change.
In other words, Lynn chose to stay at the Rengoku Residence for one night not to give himself enough time to rest, but to give Ubuyashiki Kagaya enough time to think.
When the other party thoroughly considers everything, understands what is needed to defeat Kibutsuji Muzan, and to what extent, then Lynn's plan to obtain the demon king potion can advance further.
"Don't think I'm wasting time. I'm doing this for your own good."
Seeing that Tomioka Giyu and the others seemed to want to say more, Lynn spoke first.
"Activating the Demon Slayer Mark requires sufficient physical fitness and a good mental state as support."
"If you don't rest well, even if you know the method, you won't be able to activate the Demon Slayer Mark."
"Fine."
Tomioka Giyu conceded.
Since Lynn put it that way, they would rest for the night before returning to headquarters.
...