Who is the mysterious demon that challenges Zenitsu in the Film Trailer in Infinity Castle?

Summary

• Cooling truth about Zenitsus Rival: Agatsuma is facing his old bullying in the Infinity Castle trilogy.

• Zenitsus's past revealed: Kaigaku, Zenitsus former mentor and upper rank six demon, trigger revenge.

• High-Stakes Battle: Zenit's emotional past sets the scene for a potentially intense showdown.

Demon Slayer: Kimetsu No Yaiba is undoubtedly the most popular Dark Fantasy Anime in the last decade. With its convincing stories, well -developed characters and brilliant world -building, the series has imprisoned fans all over the world. Now, after delivering season after season with better animated fight scenes and emotionally charged moments, anime is about to take things to a whole new level in Infinity Castle Arc, which will be adapted to a trilogy.

When the fans are waiting for the long -awaited first film to be released later this year, they got a glimpse of what will come through the official trailer that revealed several interesting moments. Among them they stood out because it probably left the fans with many questions. Let's decipher the mystery behind it to understand its importance to overall history.

The following contains spoilers from Demon Slayer: Kimetsu No Yaiba Manga and Anime.

An familiar enemy is waiting for Zenitsu in Infinity Castle

Agatsuma meets a familiar demon in the trilogy

Infinity Castle Trailer gave glimpses of several battles that are taking place in the upcoming film. Shinobu, who seemed more ready than ever before, could be seen fighting Doma. At the same time, Tanjiro confronted Akaza, understandably upset because of what he had done to his friend Kyojuro Rengoku. Mitsuri, Obanai, Gyomei, Sanemi and Muichiro also seemed prepared for a long battle, and knew that they might just have the chance to end Muzan's rule on terror once and for all.

The fantastic visuals beautifully captured the intense feelings that these swords probably felt right now. But a specific scene probably left many fans who scraped their heads. Zenitsu encountered a mysterious demon that looked like a sword since unloading a sword and welcomed him by saying:

Long time not see. Zenitsu.

It is clear from Zenitsu's expression that he cannot wait to fight the demon, whose first words clearly mean that the two know each other. Interestingly, the demon's face is not shown in the trailer, but it appears from his hair that he is definitely not Kokushibo, the only known demon using a sword. So who is this mysterious demon and why is agatsuma so motivated to fight him?

The chilly truth about Zenitsus rival in Infinity Castle

Agatsuma is prepared to fight against their old bullying

As fans probably remember, Zenitsu had received a mysterious letter during the Hashira training, after which he became independent and serious. He isolated himself and started training harder than he ever did before. It turns out that the letter he had revealed that his mentor, which Zenitsu gladly called Gramps, had committed Seppuku.

Many years ago, when Agatsuma trained under Jigoro Kuwajima, there was a bullying called Kaigaku who used to mock him all the time. Because of his low self -esteem, Zenitsu never stood up for himself. When he became a demon -layer, he forgot his old bullying and didn't realize that his past would come back to visit him again.

It turns out that Kaigaku had also cleared the final selection and joined Demon Slayer Corps, sometime before. During a mission he accidentally encountered upper rank, Kokushibo. Kaigaku prioritized his survival and abandoned and became a demon. When Jigoro learned the harsh truth, he decided to take his own life, of shame.

Until you die, you haven't lost. You can rub your face in dirt … you can lose your home or drink muddy water … people can curse you for stealing money … but as long as you live on … you can win a day. You will win. I have progressed with that belief. ~ Kaigaku to zenitsu

It seems that Kaigaku was later elected by Muzan to replace Gyutaro and Daki as the new upper rankings. When Zenitsu learned about everything, his old fear of death was gone immediately and he turned into a fearless warrior who had only one goal, to kill Kaigaku and revenge his Gramps.

Zenitsu and Kaigakus complicated past create the perfect emotional background for what might be one of the most intense battles in the series to date. Regardless of who wins, Zenitsus will finally be revealed.

Demon Slayer: Infinity Castle Trilogy's first payout is scheduled to be released in the US September 12, 2025.