Other than Muzan, Can Demons Turn Humans Into Demons?

Key Takeaways

• Only demons with Muzan’s blood and permission can turn humans into demons.
• Some demons, like Doma and Kokushibo, have converted humans into demons without Muzan directly present.
• Tamayo successfully converted Yushiro into a demon without Muzan’s permission through her modifications.

Warning: The following contains spoilers for the Demon Slayer manga. Demon Slayer is now streaming on Crunchyroll.

One of the things keeping the demons from Demon Slayer from being an even bigger threat than they currently are is that they can’t reproduce super fast. Muzan, the demon king, can convert humans into demons using his blood, but the demon curse isn’t like a zombie virus where every other demon can just bite or scratch a human and spread the disease. And sometimes, even Muzan can’t turn a human he wants into a demon, as some people are apparently immune to his blood. It was never really explained why some people are immune to his blood or what special properties they needed to have to be immune, but Kokushibo makes it clear that people like that are out there.

“And on rare occasions, someone resistant to demon blood appears. They do exist. But What… About You?” Kokushibo to Kaigaku, Demon Slayer, Ch. 145

So the demon curse isn’t as easy to spread as your average zombie virus, but is Muzan really the only person who can turn humans into demons? Well, while there are events in Demon Slayer where humans were turned into demons without Muzan being directly present, the answer is a bit more confusing than a simple yes or no.

It’s Possible, but Only with Muzan’s Help

Muzan’s Blood and Permission Are a Must For Most

Technically, any demon can convert humans into demons, as long as they come prepared and Muzan allows that human to turn. To go about converting people, a demon must give a human some of Muzan’s blood to ingest. It’s unknown if demons always have the blood of Muzan flowing through them that they can use to convert others, or if they have to specifically receive some from Muzan. Either way, it seems that at least the Upper Rank demons have access to some of it, as they’ve been shown a couple of times creating demons without Muzan present.

After giving a human some blood, they don’t just turn into demons right away, as Muzan has to approve of that human first. Either the demon present or the blood itself signals Muzan that a human wishes to turn into a demon, and if he meets Muzan’s standards and his body isn’t immune to the blood, then the transformation will become complete. The only other thing to note is that if the human knows Total Concentration Breathing, they will require more blood to transform than a regular human.

Instances of Demons Other than Muzan Creating More Demons

Doma Is the One Who Converted the Upper Rank 6 Siblings

The first Upper Ranks Tanjiro and his friends encountered, the Upper Rank 6 demons Gyutaro and Daki, did not personally encounter Muzan when they were still humans. Instead, they met a wandering Doma, who, at the time, was still the Upper Rank 6 demon. Doma found the two on the brink of death after the string of misfortunes they suffered and offered them a chance at vengeance by becoming demons. He provided them his blood (though he didn’t make it clear, it whould have been Muzan’s blood), and after Muzan accepted them, their demonification was complete. Eventually, Gyutaro and Daki worked their way up the ranks and became the Upper Rank 6 demons, while Doma grew even stronger and became the Upper Rank 2 demon.

Kokushibo Converted Kaigaku, Who Became the New Upper Rank 6

After the deaths of Gyutaro and Daki, a demon named Kaigaku soon stepped up and took the mantle of the Twelve Kizuki’s Upper Rank 6. Not all viewers might recall, but Kaigaku has shown himself quite a few times behind the scenes of Demon Slayer. His first appearance was during Zenitsu’s flashback in season 1, episode 17 “You Must Master a Single Thing”, as one of Jigoro’s protegees along with Zenitsu. They didn’t fully reveal his face though, only showing the lower half of it and some scenes of him facing away from the camera. Kaigaku’s second appearance was during season 4, episode 7, “Stone Hashira Gyomei Himejima” in another flashback. The events of the flashback happened before Kaigaku’s time with Jigoro and Zenitsu, revealing that Kaigaku was actually one of the orphans Gyomei took care of before joining the Demon Slayers. Not only that, Kaigaku was the child who allowed the demon to enter the temple by extinguishing the Wisteria incense that protected it.

As of the end of the Hashira Training Arc, Kaigaku has made no other appearances, but the letter Zenitsu received in season 4, episode 7 was regarding him. Although not yet shown, the letter was about the news that Kaigaku had been turned into a demon. At some point, Kaigaku encountered the Upper Rank 1 demon Kokushibo, and knowing that he didn’t stand a chance of winning, surrendered to him. Seeing potential in Kaigaku, Kokushibo offered him some of Muzan’s blood, which Kaigaku hesitantly accepted, turning him into a demon, and eventually, the new Upper Rank 6.

Tamayo Converted Yushiro Into a Demon

This case is unique because Tamayo didn’t have Muzan’s permission to do the deed. Tamayo is a demon who managed to break free from Muzan’s control and keep herself from consuming human blood by modifying her body. After the modification, she only required the occasional drink of human blood to survive. Apparently, the modification she did to herself can also be applied to humans to turn them into demons who aren’t under Muzan’s control like her. In a flashback Demon Slayer, season 1, episode 10, “Together Forever”, Tamayo recalls how she was once a medical practitioner and met the bedridden Yushiro. Knowing that he wouldn’t last long, Tamayo offered him the option of living a longer life as a demon, which Yushiro accepted.

Demon Slayer is now available to stream on Crunchyroll and Netflix. The release date for the next season of Demon Slayer, the Infinity Castle Arc has not been announced yet.