WARNING: The following article contains spoilers for Episode 21 of Demon Slayer: Kimetsu no Yaiba, "Against Corps Rules," available now on Hulu, Crunchyroll and other anime streaming services.
In the previous episode of Kimetsu no Yaiba, Giyu Tomioka intervened in Tanjiro Kamado and Rui's fight, killing the Twelve Kizuki demon with relative ease. The latest episode of Kimetsu no Yaiba, "Against Corps Rules," deals with the aftermath of the confrontation with the Spider Demon family and introduces the Hashira (literally, a pillar or post in Japanese). We've gotten glimpses at the group before in Tomioka and Shinobu Kocho, but "Against Corps Rules" reveals a much larger chunk of the team, who are the most elite members of the Demon Slayer Corps.
The episode kicks off with more of Rui's backstory, which is one of the most emotionally impactful in the series so far. Rui is revealed as having been a sickly boy, which led to Muzan Kibutsuji preting on him and turning him into a demon. His family grows fearful of him, and his father attempts to kill him with a kitchen knife in his sleep. Feeling his family fractured and the bonds between them to be false, Rui kills them all. However, just before his mother dies, she apologizes for not giving him a strong enough body.
Rui realizes his parents had intended to kill themselves after murdering him in his sleep, and then understands there was indeed a link between them. Muzan further corrupts Rui, convincing him everything that happened was his parents' fault, and Rui tries to sever his connection to his deceased parents, though he only succeeds in repressing it. This is what leads him to create the Spider Demon family, which he uses as a way to work through his horrifying history. Before he dies, he has a vision of himself in his human form, reunited with his parents. The family reconciles and embraces, just as hellfire envelops them.
Although Tanjiro recognizes Rui's grief, Tomioka walks on the demon's corpse, showing disrespect for his fallen opponent. Upon seeing Nezuko, Tomioka remembers encountering the demon girl and Tanjiro at the very beginning of the series. However, Shinobu interrupts, soaring in (literally) to kill Nezuko. Tomioka parries her blow and tells Tanjiro to run. Shinobu and Tomioka have a fairly unenthusiastic battle in which the latter is attempting to delay the former, despite the fact fighting fellow Demon Slayer Corps members is against the rules.
Tomioka succeeds in holding Shinobu back as she mocks him by claiming no one else in the Corps really likes him all that much. Shinobu isn't the only powerful slayer among those who've shown up on Natagumo Mountain, though. As Tanjiro runs away, he's knocked down and out by a woman. Zenitsu Agatsuma later identifies her as one of those who passed the Final Selection along with himself, Tanjiro and Inosuke Hashibira.
As the mysterious new demon slayer prepares to kill Nezuko, a Kasugaigarasu -- one of the series' messenger crows -- intervenes, telling the Demon Corps members on the mountain to capture Tanjiro and Nezuko and bring them back to headquarters. A knocked out Tanjiro is tied up and brought to the aforementioned headquarters, and it's implied the same happens to Nezuko. When he wakes up, he sees six of the nine Hashira.
As Tanjiro aided a demon and the Hashira appear to be violent in a way paralleling the Twelve Kizuki, there's a good chance the young demon slayer will face major consequences for harboring Nezuko. Although the personalities of the different Hashira aren't known at this time, both Tomioka and Shinobu show an incredible disdain for demons, and this seems to be a product of their elite status. Tomioka does show compassion for Nezuko, though he's seen her in action and knows she isn't a threat. Instead, Nezuko is an exception to the idea all demons kill without mercy. Plus, Shinobu's taunting indicates he might not exactly fit in with the rest of the team very well.
Considering his broken sword and the immense strength of just Shinobu and Tomioka, Tanjiro doesn't stand much of a chance of fighting his way out of the situation. However, if the Hashira wanted Nezuko and Tanjiro dead, they'd already be gone. The title of the next episode, "Master of the Mansion," promises to bring Tanjiro face-to-face with someone in a position of power, so there will likely be a reprieve of some sort. Still, the Hashira already serve as a testament to what Tanjiro could be like if he chooses to give up the compassion that defines his character. However, Tanjiro and Nezuko might also just end up serving to prove humans and demons can co-exist.
New subtitled episodes of Demon Slayer: Kimetsu no Yaiba air Saturdays on Hulu, Crunchyroll and other anime streaming services.