Afterward, at Kagaya's request, Riezel helped all the Hashira remove the Demon Slayer Mark from their bodies.
It was understandable, as it was a deadly ability, after all.
If Riezel hadn't helped them remove the Demon Slayer Mark, they wouldn't have lived past twenty-five years old. Moreover, Gyoumei, who was already twenty-seven years old, would have died immediately without any luck.
Since the birth of the Demon Slayer Mark, only one person managed to survive with it, and that was Yoriichi.
Riezel didn't know how Yoriichi managed it, as the original work didn't ever mention it.
Perhaps Yoriichi survived because his Demon Slayer Mark was naturally born with him, so it didn't exhaust his lifespan, allowing him to live. Or perhaps he had found a way to neutralize its side effect before turning twenty-five.
In the end, no matter what reason, Yoriichi was Yoriichi—his existence was special and a genuine cheat that the Hashira could not compare at all.
For this reason, continuing to keep the Demon Slayer Mark would only lead to their demise.
In this way, Riezel used the Decomposition Magic to decompose the Demon Slayer Mark on the Hashira.
Without the Demon Slayer Mark, the Hashira couldn't even use the Bright Red Nichirin Sword, and only the Transparent World remained usable among the three abilities.
However, since Tengen, Shinobu, and Mitsuri didn't even have the Transparent World, they were the ones who truly reverted to their original state.
Nevertheless, with demons now nonexistent, they no longer needed such abilities.
And so, with the Demon Slayer Corps officially disbanded, all Demon Slayers would put down their swords and return to normal society, living normal lives.
Kyoujurou would inherit the Rengoku family's business, attempting to transform his long-standing family of Demon Slayers.
He apparently intended to open a dojo where future apprentices would come to learn his family's swordsmanship, making the dojo the main focus of the Rengoku family.
Shinobu would continue to manage the Butterfly Mansion, but it would no longer serve just the Demon Slayer Corps. It would now cater to the general public, treating people's illnesses.
Obanai seemed determined to confess his feelings to Mitsuri, so if they were to marry soon, it seemed likely.
On the other hand, since Tengen was already married with three wives, the four of them planned to settle down somewhere and live a secluded life.
Gyoumei, Sanemi, and Muichirou expressed their intention to remain with the Ubuyashiki family, continuing to serve it.
As for Giyuu, he seemed to want to return to his master, so what he would do in the future, only he knew.
As the Hashira each made their own plans, Tanjirou, Zenitsu, and Inosuke also planned to return to the Kamado family with Nezuko to go back to their old lives.
Of course, after the disbandment of the Demon Slayer Corps, the Ubuyashiki family wouldn't ignore them—whether it was the Hashira, Tanjirou and the others, or even the ordinary members and the Kakushi.
From the start, the Ubuyashiki family had planned to help them integrate into normal society and live normal lives, at least financially, ensuring they wouldn't have to worry for the rest of their lives.
Under these circumstances, even the Swordsmith Village was preparing to open up to the outside world. They would no longer hide but would rely on their forging occupation as their main economic source, serving the whole country.
With the assistance of the Ubuyashiki family, everything would proceed orderly in the future.
It could be said that those who survived would have a bright future ahead, living their lives worry-free.
Kagaya, Kyoujurou, Tanjirou, and the others had asked Riezel about his plans for the future, but he simply replied with one sentence.
"I'll return to the place where I belong."
Riezel said only that and thereafter said nothing more.
However, one thing was certain—his mysterious answer left Kagaya, Kyoujurou, Tanjirou, and the others with a feeling that once he departed, they would never meet him again.
Nevertheless, they did not dwell on this feeling excessively.
===
Meanwhile, at the entrance of the Swordsmith Village, everyone gathered together to bid farewell.
"Us Ubuyashikis will always remember you, Your Excellency."
Kagaya declared firmly, yet his face remained gentle.
"You are welcome to visit my dojo anytime."
Kyoujurou added, with an unusually gentle expression, embracing Riezel.
"Thank you for everything, Big Brother."
Tanjirou spoke sadly, shedding tears, but after wiping them away, he smiled broadly at Riezel.
Seeing them like this, Riezel revealed something to them at this final moment.
"Actually, my name isn't Tsugikuni Yoriichi."
Riezel suddenly smiled at everyone.
"My name is Riezel."
At this point, Riezel finally revealed his true name to them.
""Riezel...""
Kagaya, Kyoujurou, Tanjirou, and the others murmured the name in a daze.
When they came to their senses, Riezel was already gone, vanished like a ghost.
On this day, Riezel officially left the Swordsmith Village, left the Demon Slayer Corps.
Whether it was the Demon Slayer Corps or the people of the Swordsmith Village, no one ever saw him again after that.
Even so, Riezel's name remained forever.
Many years later, people would discover some peculiar things.
For instance, in a dojo called the 'Rengoku Hall', on a wall of honor, the name 'Riezel' was engraved in the front row.
On the other hand, the ancestors of the Ubuyashiki family often mentioned to later generations a great swordsman and hero named 'Riezel'.
Meanwhile, in a charcoal-selling family deep in the mountains, there was a group photo of all members of the Demon Slayer Corps, with an empty space in the center where a mechanical doll stood holding a tag inscribed with the name 'Riezel'.
Even in a private medical enterprise called 'Butterfly', it was said that there was a female pharmacist who made significant contributions to the medical field, never married, and dedicated her life to researching a medicine capable of curing various illnesses—a medicine named 'Riezel'.
However, these events took place a very long time later.
===
At this moment, as Riezel left the Swordsmith Village, he paused his footsteps as he entered a deep mountain area.
Ahead of him were two figures.
It was none other than Tamayo and Yushirou.
"Are you leaving?"
Tamayo asked, her serene face no longer bore the sorrow and resentment of the past, replaced by a sense of relief.
"Yeah..." Riezel nodded calmly. "Are you here to see me off for the last time?"
"...I guess so." Tamayo smiled gently. "Though I really want to thank you, you've probably heard enough of that, so I'll just keep it in my heart."
"Hmm, is that so?" Riezel smiled knowingly. "What are your plans now?"
At his question, Tamayo lowered her gaze.
"I've successfully developed a cure for demon transformation." Tamayo explained softly. "I've analyzed all the blood left by Muzan from the previous battle in the Infinity Castle, and finally developed the cure."
"Oh?" Riezel was taken aback for a moment, then understood. "So you're planning to take this cure and become human again?"
"...Whether it's me or Yushirou, if there's a chance to become human again, we won't hesitate." Tamayo nodded gently. "Creatures like demons shouldn't exist in this world any longer."
Muzan's death had eradicated all demons, except for Tamayo and Yushirou.
Using her medical knowledge, Tamayo had seized the opportunity centuries ago to transform her body and free herself from Muzan's influence when he was severely injured by Yoriichi and too weak to control her.
As for Yushirou, he was the only demon in this world who wasn't transformed by Muzan's blood. He was transformed into a demon by Tamayo when he was dying, thanks to her centuries of research on demons.
Because of this, Muzan's death didn't affect these two.
Now, only Tamayo and Yushirou remained as demons in this world, while all others had vanished.
Apart from Riezel, few knew about this fact, except for the Ubuyashiki family.
However, Kagaya seemed unwilling to interfere with Tamayo and Yushirou.
From this, it was clear that Kagaya chose to trust Tamayo, believing that even as a demon, she would not fall into depravity.
Needless to say, Tamayo and Yushirou could live on as demons forever, never aging or dying.
Tamayo also knew of the existence of the Blue Spider Lily, so with her medical abilities, developing a drug to overcome sunlight wouldn't be difficult.
In time, Muzan's dream of eternal life and perfect existence could be realized through Tamayo and Yushirou.
Yet, Tamayo seemed reluctant to do so.
It was clear that she didn't want to be a demon but wanted to return to her origins as a human.
Even if it meant a limited lifespan, it didn't matter to her.
Having avenged her deep-seated grudge and lived in this world for centuries, she had had enough.
Now, she only wished to pass away peacefully as a human.
With Tamayo making this choice, it was natural that Yushirou couldn't continue to live as a demon by himself.
With this in mind, once the effects of the demon transformation cure were fully confirmed and no problems arose, both of them would likely take the cure directly and return to being human.
In that way, the last two demons in the world would disappear.
"Please take this."
Tamayo suddenly handed a small bottle to Riezel.
"What's this?"
Riezel took the bottle and asked confusedly.
"This is a medicine I developed by thoroughly diluting Muzan's blood. It can temporarily give humans a regenerative ability comparable to a demon's—the only one of its kind in the world."
Tamayo explained slowly.
"If you take it, even the most severe wounds will heal instantly, and it can even revive people who haven't been dead for too long."
A medicine that could revive people!
Seeing such a miraculous medicine in his hand, Riezel couldn't help but be amazed!
"Consider it a token of my gratitude to you."
Tamayo bowed to Riezel, bidding farewell.
"If fate allows, maybe we'll meet again."
With that, Tamayo disappeared with Yushirou.
Riezel watched them leave, and after a long while, he finally stored the medicine away.