Demon Slayer season 4 ending explained: How episode 8 sets up Infinity Castle movies

Because yes, everything this season has been lacking suddenly came into sharp focus for season 4's eighth and final episode when Muzan Kibutsuji arrived. The Hashira unite, just as the episode's title suggests, but no, it's not for a party or a mochi feast either. It's for a far, far darker reason than that.

Demon Slayer season 4 ending explained: Who dies in the finale?

At the end of the previous episode, Muzan Kibutsuji began walking into Ubuyashiki's home. One week later, he's still doing it, and for even longer this time around. Boy does this guy love the drama, and we are here for it.

The animators are too if all the dazzling effects around Kibutsuji are anything to go by. Yet even with all that build-up, Ubuyashiki and his family do nothing to try and stop him or escape. To confront such a powerful demon would be futile, plus it seems the patriarch of the entire Demon Slayer core has a trick up his sleeve.

Through some genuinely fascinating exposition, we discover that the pair are in fact related and that's why the men in Ubuyashiki's family are cursed to be born frail and sickly, including him. It's karmic retribution for producing such an awful monster who's responsible for the deaths of so many. Seems kind of harsh, but no matter. Ubuyashiki has been holding on to life in the face of his own certain death to try and break free of this vicious cycle.

Killing Kibutsuji wouldn't just end that karmic journey. It would also result in the deaths of every demon ever, so the stakes are high. But how could such a fragile human hope to defeat the show's Big Bad? If Ubuyashiki dies, he knows that the rest of the demon slayer core will still live on, so he decides to end it once and for all with a humongous explosion.

The blast is immense and devastating, instantly wiping out Ubuyashiki and his entire family, not to mention the entire estate. Did his creepy kids need to die as well for this plan to work? Our mind says no, but our heart says yes, because they really were the creepiest kids and it's safe to say no one will miss them.

So yep, Ubuyashiki is now dead, but it's all part of his plan to defeat Kibutsuji once and for all. The explosion wouldn't kill him, of course, but it certainly slows him down, especially with the addition of some materials toxic to demons, thereby slowing down Kibutsuji's regeneration process.

Let's talk for a second about how beautifully animated that was. And by "beautiful", we mean, "It was absolutely disgusting in the best way possible." Half of his face is gone, and the rest of his body looks like Swiss cheese too. But this all just goes to show precisely how powerful Kibutsuji really is because he still survives, even through all that.

The series has frustratingly sidelined Kibutsuji more than necessary in the past, detracting a bit from the gravitas of this final confrontation, but the finale more than makes up for this with moments like these.

While Kibutsuji is recovering, Tamayo is the first to jump in, using her blood demon art to trap Kibutsuji and delay his healing process even longer. But even impaling him with blood spikes through his skull and entire body aren't enough to fell the demon king, and Tamayo knows that. She's just buying time for the others to arrive.

Via flashback, we learn that the plan is to defeat Kibutsuji using the sun, his only weakness. Not even decapitation works on him like it does the other demons, so everyone must work together to trap him outside long enough for the rising dawn to take Kibutsuji out for good.

Demon Slayer sure does love a mid-battle flashback, often at risk of slowing down the episode's entire momentum, but we'll forgive this one because of what comes next.

Once again, Kibutsuji gives us more nightmare fuel with yet another gruesome regeneration, but hopefully the nightmare will end now that Tanjiro and the Hashira have finally shown up to put all of this season's training to good use.

Each set up their signature moves at the same time, rushing in with what promises to be the most epic, incredible moment in all of anime – no, all of animation... nay, all of TV!! – but then Kibutsuji pulls out one final trick that stops everyone in their tracks...

How does Demon Slayer season 4 set up the Infinity Castle movie trilogy?

Using his crazy demon lord powers, Kibutsuji pulls everyone into his Infinity Castle, a realm where up is down, left is right, and victory is snatched away at the very last moment. Yep, Kibutsuji really is that b***h. But the fight's not over just yet.

Following this literal twist of a cliffhanger, Studio Ufotable revealed that the final Demon Slayer arc – not-so shockingly titled Infinity Castle – won't air as a regular season on TV. Instead, the last big battle will unfold across not one, not two, but three movies set to be released in cinemas within the next year.

If season 4 will be remembered as the slowest, perhaps most light-hearted season, what follows next will undoubtedly be the most fast-paced and devastating Demon Slayer has ever been. Not everyone will make it out of the Infinity Castle alive, including us if the twists prove too shocking, which we're sure they will.

Watch a trailer for Demon Slayer: Kimetsu no Yaiba Infinity Castle below:

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