Tanjiro‘s main goal in Demon Slayer is to heal Nezuko, and after Gyutaro’s defeat, he’s closer to his goal than ever.
It’s easy to forget that Tanjiro Kamado’s ultimate purpose in Demon Slayer: Kimetsu no Yaiba isn’t merely to slaughter demons. While slaying Muzan Kibutsuji’s demons is a necessary evil, Tanjiro’s actual purpose is to bring his sister, Nezuko, back to life. In Season 1, Lady Tamayo, a demon herself, told Tanjiro that she could cure demonism if she could analyse the blood of a demon with a large amount of Muzan’s blood. Only a powerful demon could do the job, and Tanjiro did so by stealing a sample of Gyutaro’s blood near the end of Season 2’s “Entertainment District” arc.
In the same attack that killed the rest of her family, Nezuko Kamado was turned into a monster, and Tanjiro never gave up hope of finding a means to restore her to normalcy. When the two met in Season 1, Tanjiro’s unwavering optimism and unending generosity, even to devils, helped convince Tamayo to trust him. Tamayo is a highly qualified doctor and pharmacist (kind of), and his helper, Yushiro, is the only person other than Muzan who has created a demon. Tanjiro donated a sample of Nezuko’s peculiar blood at Tamayo’s request so that he could research it while continuing his mission to exorcise demons and hopefully finding a member of the Twelve Kizuki whose blood he might return to aid Tamayo.
Tanjiro has shown to be a brilliant swordsman and a lethal issue magnet since joining the Demon Slayer Corps. Tanjiro had a run-in with four members of the Twelve Kizuki towards the end of the “Entertainment District” arc: Rui (Lower Five), Enmu (Lower One), Akaza (Upper Three), and Gyutaro (Upper Three) (Upper Six). Unfortunately, Tanjiro was too badly injured after his fights against Rui and Enmu to collect blood during his first three encounters with the members of the Twelve Kizuki. It wasn’t until his victory over Gyutaro that Tanjiro was able to take the opportunity to do what Tamayo asked of him by sending him a blood sample.
Tamayo now has the blood of Nezuko and a member of the Twelve Kizuki, as she requested, and it may only be a matter of time before she creates a cure for demonism. Given that Muzan commanded his demons to kill the Kamado siblings, it’s unclear whether Tanjiro and/or Nezuko will live long enough to see the fruits of Tamayo’s labour. Muzan Kibutsuji is not a fan of Tanjiro’s Sun-Breathing technique, and it frustrates him that Nezuko has gotten out of hand. As Demon Slayer progresses, Tamayo will be racing against the clock to find a treatment for Nezuko before Muzan discovers the Kamados.
Someone more pragmatic than Tanjiro might prefer Nezuko to stay a demon, given her Blood Demon Art is the Demon Slayer Corps’ most powerful weapon. After all, if Nezuko hadn’t utilised her Blood Demon Art to heal Tengen Uzui, Tanjiro, and Inosuke Hashibira, they would have all died from Gyutaro’s poison. Nezuko’s Blood Demon Art appears to be able to negate other Blood Demon Arts while only harming other demons. While some Demon Slayer Corps members still regard Nezuko as a liability, she may be an even greater value than the Hashira.
If history is any indication, further trouble is on the way for Tanjiro and Nezuko, even after a High Rank’s first defeat in 100 years. Muzan summoned Akaza and possibly others to the Infinity Castle, which means the demon spawner probably isn’t thrilled that Gyutaro was killed. As the heroes recover from their most recent battle, the countdown to the next inevitable war begins. Now that Tamayo has received the blood sample she requested, it’s officially on the table whether Nezuko will be a demon or a human the next time a High Rank decides to take a chance on ending the siblings. Kamado once and for all.
