Demon Slayer: Infinity Castle was one of the most anticipated movies of all time. Upon release, Demon Slayer It became an instant hit both in Japan and internationally. It featured some high-octane battles like Giyu and Tanjiro vs. Akaja, but it also kick-started the Doma War, which saw the official defeat of Hashira Shinobu. That said, Shinobu's death doesn't mean the battle is over.
Demon Slayer: Infinity Castle Part 2 will officially see Kanao and Inosuke continue this fight, and thanks to that, we'll get to see one of Hashira's abilities known as the Vermillion Eye. This ability was previously the flower Hashira Kana's, and it would be used by Kanao to its full potential, unleashing the flower's true ability to breathe in the process.
Demon Slayer Infinity Castle Part 2 Officially Reveals Hashira's Power 'Vermillion Eye'
Demon Slayer: Infinity Castle was a blockbuster hit from 2025, and it features some intense battles highlighting Tanjiro and the other Demon Slayers, who enter Infinity Castle to deal with the threat of demons once and for all. Muzan gathered his strongest demons in the Infinity Castle to fight Hasira's threat, and among them we saw 2 upper rank demons, Doma. Doma fought Shinobu, and despite the insect Hashira's best efforts, she died and was consumed by this monster.
However, with Demon Slayer: Infinity Castle Part 2, we will see the Doma War resume. With Shinobu out, we already have the perfect setup for Kanao, her younger adopted sister, to enter the fray. Along with him, he will have the support of Insuke. Kanao will especially shine in this fight, and in large part, it's thanks to his swordsmanship style. Kanao would proceed to use Flower Breathing, the same breathing style used by the former Flower Hashira, Kana. Kanao is also Kana's younger adaptive sister, and because of this, she is able to learn Flower Breathing directly from him. With a perfect set-up, the upcoming Demon Slayer movie will see Kanao set to demonstrate his ultimate ability of Flower Breathing, which, in Gotzu's story, is one of Hashira's most deadly powers.
“Why did you say that? You were ready to sacrifice your life, so why bother with my vision? She was such a kind person, so precious! I wanted to protect her. I wanted to risk my life for her. I wanted to go home together. Flower Breath Final Form: Equinoctial Vermillion Eyes.” – Kanao in Demon Slayer Chapter 162
In his battle against Douma, Kanao would finally unleash his final form: the Equinoctial Vermillion Eye. This eye ability is extremely powerful, as it allows the user to perceive the world in slow motion by increasing blood flow to the eyes. It takes the user's vision to its maximum potential, and their perception surpasses all others. This technique was first revealed in Demon Slayer Chapter 162, which was released in Weekly Shōnen Jump issue #29 on June 17, 2019. Kanao activates this technique in the final stretch against Doma. Using this technique, Kanao was able to see through Douma's technique and move forward, allowing him to land a final blow and cut off his head.
“Extremely enhancing dynamic vision…movement around seems slow and sluggish. My eyes bleed from the pressure causing them to stain red…” – Kanao Demon Slayer in Chapter 162
The strengths of this technology are such that it comes with a major downside to discourage users from using it. When this technique is used, there is a high chance of going blind in one eye, which is what happened to Kanao. However, its upsides outweigh the risks in a fight to the death.
Kanao will use the Vermilion Eyes again in Infinity Castle Part 3 to stop the Demon King Tanjiro.
Vermilion Eye has proven to be one of the most important abilities in the entire Demon Slayer series. Not only was it decisive in the victory against the Upper Rank 2 Demon Doma in Infinity Castle, but it would be crucial again in the final movie, Infinity Castle Part 3. The final movie of the trilogy will focus on the fight against Muzan, but in the end, the heroes have a new villain fighting over them. After Muzan is finally defeated by Hashira, he transforms Tanjiro into the new Demon King in his last ditch effort.
Tanjiro becoming the new Demon King would have completely destroyed humanity, especially since this new Demon King had greatly surpassed Muzan. This disaster cannot be stopped without Kanao and his Vermillion Eye. Left with one eye after the Battle of Doma, Kanao activates the Vermillion Eye and injects Tanjiro with an antidote created by Shinobu. No one else could achieve this great transformation of Tanjiro, which goes to show the strength of this final form. Of course, after this second experiment, Kanao goes completely blind, but in the process, she saves all of humanity, which is a worthwhile sacrifice in the grand scheme of things.
Why didn't Kana use vermillion eyes on the Demon Slayer
Kanao has always been our main window to flower breath throughout the story, especially when it comes to the Vermillion Eye. However, she did not invent flower breathing. Like Snake Breathing, Flower Breathing derives from Water Breathing, which in turn derives from Sun Breathing. The original creator of Flower Breathing is unknown, but its first known user in Demon Slayer is none other than Kana Kocho, Shinobuki's older sister. Kana Kocho, with her Flower Breath, became a powerful Hashira, known as Flower Hashira. She is the one who taught Kanao everything there is to know about this power, including the final form: the Equinoctial Vermillion Eye.
Sadly, Gotouge was never given a full look at Kanae's power, her Doma battle was mostly off-screen. That being said, we do know that, for whatever reason, she never used her final form because Shinobu had a vision of her when he found her on the brink of death after the battle. On the other hand, Kana never used the Vermillion Eye's power because her plan was to stop Doma and survive until sunrise, which she almost managed to do.
Vermilion Eye is powerful, but it is a quick power boost that puts the user at risk of blindness in one or both eyes afterwards, and is only used as a last resort. Kana didn't use it because the risks outweighed the benefits, and that's why Kanao kept this power until the end of the Doma War. This is yet to be Hashira Power at its best, and we can't wait to see how Ufotable highlights it in the next movie.
Demon Slayer: Infinity Castle Part 2 is expected for a 2027 release, although this is currently unconfirmed. New information should be revealed later this year.
