Demon Slayer: Kimetsu no Yaiba is arguably one of, if not the most talked-about manga and anime series of all time, with Mugen Train breaking yet another Ghibli record. Koyoharu Gotouge's masterpiece is full of multi-layered characters, and Demon Slayer's demons are proof of the effort they put into giving them depth.
Even if you're not a fan of the show (yet!), basic common sense would tell you that it has to do with demons and slaying them. But one of the beauties of this anime is how almost every character is given a coherent and sympathetic backstory—yes, even the dreaded demons. Here are 6 things you should know about them.
Warning: Major spoilers ahead!
Can Demons Eat Other Demons?
It's a given that Demon Slayer's demons devour humans to increase their strength. What's not very openly explained or even hinted at is whether they eat fellow demons or not.
The truth is that it's not even a question of whether or not they can.
For starters, demons possess immense strength. If they ever wanted to, they could definitely attack other demons with intentions of making a meal out of them afterward, albeit laboriously since, again, demons are impossibly strong.
Secondly, Lady Tamayo, a demon who doesn't rely on human flesh to survive, mentions that cannibalism isn't possible among demons. This owes to a rule or truth that has been established, more or less implying that they could only gain strength by consuming humans or by drinking Muzan's blood, essentially making cannibalism an unnecessary and pointless risk.
Given these, it's obvious that demons would rather not eat other demons, even if they could in theory.
Related: Is the Demon Slayer Manga Complete, Finished or Ongoing? Here's the Current Status
Can Demons Kill Each Other?
Like we mentioned above, the show's demons are so strong, a fight between any two could take a while before a winner could emerge. This doesn't apply to Muzan, of course, who could very easily kill other demons. Not surprising, considering his control over them as Japan's Original Demon. (While we're on the topic, read about some shocking Muzan Kibutsuji bombshells here!)
The demons' seemingly infinite life count can be directly traced back to their incredible regeneration capabilities, which scale in speed according to their power and how much they've evolved (through eating human flesh, no less). Stronger demons could even regrow their decapitated heads!
For demons other than Muzan, the only way to kill other demons would be to wait till daybreak and expose them to their biggest and most fatal weakness, sunlight.
Can Demons Eat Human Food?
The shortest and most straight-to-the-point answer in this article so far is also the most logical. Save for those who have made modifications to their bodies for various reasons like Lady Tamayo has, demons don't eat human food simply because they can't process them.
We say 'logical' because this concept is reminiscent of that of Tokyo Ghoul's, where ghouls like Kaneki and Touka are unable to eat human food as it has become disgusting to them after transforming. Though not as specifically discussed, demons in Demon Slayer more or less have the same problem with human food, since if they do attempt to have some, they only end up throwing it back up.
Can Demons Use Breathing?
In Demon Slayer lore, the term "Breathing Styles" refers to the swordsmanship styles taught within the Demon Slayer Corps. These breathing techniques enhance a Demon Slayer's weapons and fighting abilities. It's imperative that Demon Slayers practice and master these styles if they are to even dream of defeating these exceptionally strong demons. Rengoku's Total Concentration Breathing Style is a very good example.
But these swordsmanship styles are not exactly exclusive to the Demon Slayers. In the series, there are at least two demons who have been known to use Breathing Styles: Kokushibo and Kaigaku.
However, these two have used Breathing Styles as humans and carried the techniques over when they turned into demons. Therefore it isn't very clear if demons are, in fact, capable of learning and mastering Breathing Styles in their current form.
Can Demons Reproduce?
Demon Slayer's demons can reproduce for sure. As Giyu explains to a shaken Tanjiro while singlehandedly holding down a Nezuko-gone-berserk, a human turns into a demon when their blood gets tainted with demon blood, like through an open wound, for instance. That's how demons multiply.
So no, they don't have babies, if that's what you're asking. Any child a demon might have would have been from when they were still human.
But this begs the question of why and how Muzan had a child. While this is yet another detail that isn't widely explored in neither the manga nor the anime, it is not so impossible to make sense of if we put together the bits and pieces we are given throughout the series.
Here's what we came up with after some snooping:
Since Muzan can shapeshift, it's highly likely that he's transformed into some of the people he's killed, with the original father of the family he's using as a cover being one example. The other possibility we came up with is less conspiratorial in nature. It may just be that he did woo a woman (still for cover-up) who's already had a child before meeting him. Who's to say how many times he's done that, especially since he'd already lived hundreds of years before meeting Tanjiro.
Then again, nothing in the manga supports nor debunks these theories, so anyone's guess is as good as ours!
Can Demons Age?
Demons can age, although at a much slower rate than regular humans do that it's essentially invisible to the regular human eye. Biologically, they're immortal, which means them aging doesn't necessarily mean they'll die because of old age even trillions of years later.
That's it! That's all we're saying about the demons' aging process. Any further and we might as well serve you the ending on a silver platter.
These are all strong indications of how thoroughly and carefully crafted the world of Demon Slayer: Kimetsu no Yaiba is. Pretty cool, right?
If you enjoyed the hit series, here are three anime like Demon Slayer that you should really start watching!
For more articles like this, take a look at our Anime and Demon Slayer page.