This article details the events for the final arc of the Demon Slayer manga.
Demon Slayer introduced us to its final saga in anime form through its most recent film, titled Demon Slayer: Infinity Castle Part 1 – Akaja's Return. This movie served as an entry point to the final part of the story, but there is still more material to come. The Demon Slayer is returning with two new movie installments, which fans currently know as Infinity Castle Part 2 and 3.
We are all extremely excited to see the upcoming battles, especially when it comes to Hashira, who forms the strongest battle force of the Demon Slayer Corps. The next big Hashira battles are officially set to take place against Kokushibo and Muzan. To combat their power, Hasira needs a massive power-up. Demon Slayer's author, Koyoharu Gotoge, has already established incredible power-ups for them, with the ultimate Nichirin Blade upgrade, called Bright Red Nichirin. Gyomei, Sanemi, Muichiro, Obanai and Giyu are all soon to tap into this power.
Demon Slayer Infinity Castle Part 2 and 3 will empower Hashira with a bright red Nichirin sword.
The first Demon Slayer Infinity Castle movie was released in July 2025. Since then, we have been waiting for new updates related to the upcoming two movies, but nothing has been revealed to us so far. Regardless, the project is definitely in production, and we expect these movies to arrive in 2027 and 2029, respectively. The upcoming releases of Demon Slayer will bring even bigger challenges for our heroes. Notably, we're looking forward to the battle against the upper rank 1 Kokushibo, as well as the battle against the Demon King himself, Muzan.
To combat them, Hasira already has a few power-ups, but we're especially excited to see the bright red Nichirin Sword in their hands. In Infinity Castle Part 2, Gyomei, Sanemi and Muichiro are all set up to unlock this power in their battle against Kokushibo. In Infinity Castle Part 3, Obanai and Giyu will tap into it to damage Muzan, and it will be fun for us to witness all these events.
How Muichiro, Gyomi, and Sanemi Tap to Get the Bright Red Nichirin Swords vs. Kokushibo
While we were all impressed by the strength and power of Upper Rank 2 Doma and Upper Rank 3 Akaza, Muzan's strongest underlings had yet to make their entrance. The Upper Rank 1 Kokushibo is a monstrous demon that possesses the powerful Blood Demon Art in combination with Moon Breathing, a brand new type to be revealed in the film. Due to his ability and quick regeneration, Kokushibo will be the toughest fight yet for Hashira, especially Muichiro, Sanemi and Gyomi.
In the manga, this fight was brilliantly portrayed by Gotuge, and we can see that even though they were fighting well, they were unable to deal any lethal damage to Kokushibo, up to a certain point. Meanwhile, the latter grew stronger, and surprisingly, he was even able to regenerate from a beheading, which, for most demons, is a fatal blow from which they do not come back.
Kokushibo uses strange powers, and to defeat him, in a moment of pure determination, it goes without saying that Hashira has finally upgraded. In Demon Slayer chapter 175, Weekly Shōnen Jump issue #43, released on September 21, 2019, Muichiro, the youngest, was able to awaken a bright red sword, through pure pressure on his Nichirin Blade. Muichiro then stabbed Kokushibo, causing the demon to suffer excruciatingly. With that moment of distraction, Gyomi and Sanemi put their forces together, and in that same chapter 175, the two clashed their weapons, heating them up and their swords turning bright red. With their bright red weapons activated, they were finally able to cut Kokushibo's head off once again, and this time, for good.
Obanai and Giyu will officially receive the bright red Nichirin Sword against Muzan
Kokushibo could not be defeated without the 3 Hashira receiving the Bright Red Nichirin Blades that fought him head-on. However, Hashira will need this sword upgrade once again in the final movie, which will see them fight a final enemy that is much stronger than Kokushibo, the King of Demons himself, Kibutsuji Muzan. In the final movie, Muzan is heavily nerfed as he is affected by the anti-Muzan potion, which slows down his regeneration. Despite that, he still stands as the greatest of all demons. Muzan regenerated so fast that even the splinter on his neck instantly healed as if nothing had happened to him.
In her case, Hashira's goal was not to kill the demon with her sword. Instead, they were looking for every way they could to hold him off until morning and deal with the light. Not that Hasira didn't put up an exciting fight against him. More Hashira unlock a bright red sword against her, and among them is fan favorite Obanai. Obanai, like Muichiro, unlocked this upgrade by applying pressure to his sword after obtaining his Demon Slayer Mark in Demon Slayer Chapter 189, released in WSJ Double Issue #6-7 on January 3, 2020. The pressure used to activate the Red Sword officially strengthens his power. At the same time, he gives Gyomei and Sanemi an opening to reactivate their Bright Red weapons as well.
in Demon Slayer In Chapter 190, we will also see Giyu tap into the Bright Red Sword with Sanemi's help. Giyu's blade awakens as Sanemi and Giyu's weapons clash. Giyu is also able to momentarily tap through Tanjiro's blade into a bright red sword. The two then do their part in Demon Slayer Chapter 199 to hold off Muzan until the sun rises in the final part of the battle.
Why the bright red Nichirin Sword is the ultimate blade power up in Demon Slayer
Bright Red Nichirin is undoubtedly the ultimate power-up that any sword user can achieve in Demon Slayer. However, it is said that this power-up does not permanently change the sword. Instead, it is temporary, but a demon slayer can tap it multiple times if they know how to activate it through pressure, friction, or ignition.
“His blade is turning red? What is it?! My body is hardening! It hurts! My insides are like fire! This technique won't come out! This tree has sprouted from me?! This trunk must have grown from drinking my blood! And this pain! It's hardening my body! It's because of the red word like a red blaze! Yorichi's…” Kokushibo after being stabbed by Muichiro's Bright Red Nichirin in Demon Slayer Chapter 175
The bright red Nichirin is strong as it resembles the bright flames of the sun. Yorichi's own blade was naturally bright red. As such, this light sword deals the most damage to a monster. Stabbing with a bright red sword is extremely painful and burns their insides. This also has a huge effect on their regeneration, which must happen in the final arcs where monsters can even regenerate their own heads.
Unfortunately, the only Hashira present during the Muzan battle who was not able to tap into the bright red Nichirin was Mitsuri. He didn't use any of the Demon Slayers' ultimate powers in the final battle, and this could be explained by the author sidelining him through this high-stakes battle.
All chapters of Demon Slayer, by Gotouge, are available to read through Manga Plus and Viz Media.
