Third season of Youkoso Jitsuryoku Shijou Shugi no Kyoushitsu e.

A special scientific experiment, a wonderful adventure in different time and space. Jun Changxiao came to Xingyun Continent with the system and inherited an unknown small sect. He must build the sect into the No. 1 in Xingyun Continent within a hundred years, and recruit 100,000 disciples. If he fails to complete it, the system will explode and he will be finished. In order to survive and return to the original time and space safely. He actively "established a sect" and taught disciples. The gang grew from a "lone commander" to a hundred people. Under the leadership of Jun Changxiao, everyone built houses and planted crops, caught chickens and found dogs, and maintained peace and helped the weak anytime and anywhere. The disciples in the sect have different personalities. The funny Jun Changxiao gets along well with everyone, and there is unlimited joy in the warm big family. In a lively and positive atmosphere, everyone supports each other and grows rapidly. The cultivation of the sect is a long and arduous task, and Jun Changxiao leads the disciples to explore up and down... (Source: Tencent, Google translated)

For centuries, the Demon Slayer Corps has sacredly kept the location of Swordsmith Village a secret. As the village of the greatest forgers, it provides Demon Slayers with the finest weapons, which allow them to fight night-crawling fiends and ensure the safety of humans. After his sword was chipped and deemed useless, Tanjirou Kamado, along with his precious little sister Nezuko, is escorted to the village to receive a new one. Meanwhile, the death of an Upper Rank Demon disturbs the idle order in the demon world. As Tanjirou becomes acquainted with Mist Hashira Muichirou Tokitou and Love Hashira Mitsuri Kanroji, ferocious powers creep from the shadows and threaten to shatter the Demon Slayers' greatest line of defense. [Written by MAL Rewrite]

The devastation of the Mugen Train incident still weighs heavily on the members of the Demon Slayer Corps. Despite being given time to recover, life must go on, as the wicked never sleep: a vicious demon is terrorizing the alluring women of the Yoshiwara Entertainment District. The Sound Pillar, Tengen Uzui, and his three wives are on the case. However, when he soon loses contact with his spouses, Tengen fears the worst and enlists the help of Tanjirou Kamado, Zenitsu Agatsuma, and Inosuke Hashibira to infiltrate the district's most prominent houses and locate the depraved Upper Rank demon. [Written by MAL Rewrite]