Demon Slayer Infinity Castle trailer gives Zenitsu more aura than the manga ever did

With the upcoming Demon Slayer Infinity Castle film series, Ufotable dropped a trailer on June 28, 2025, right before the Japanese release on July 18. With the entire premise of the trailer focusing on the major battles between the Slayers and the demons, one character was depicted in a different light.

A battle between the new Upper Moon Six demon Kaigaku and Zenitsu was also featured briefly. However, the Zenitsu shown in the trailer was very different from the one the fans usually know in the manga.

Disclaimer: This article reflects the author's opinions and contains potential spoilers from the Demon Slayer anime and manga.

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Zenitsu returns with a different aura in the Demon Slayer Infinity Castle trailer

With the recent drop of the Demon Slayer Infinity Castle trailer by Ufotable, Zenitsu was portrayed in a different personality altogether. Although brief, Zenitsu radiated a more collected and serious aura around his presence, which indicated his massive change in personality, which was hinted at earlier in the Hashira Training arc.

From the very beginning of the series, Zenitsu was shown as an anxious and unenthusiastic individual who was scared by just the idea of battle. However, that was just the conscious Zenitsu. Whenever he fell asleep, something changed in him, and all of a sudden, he became a formidable opponent who mastered the art of Thunder Breathing.

Most of Zenitsu's feats so far in the anime series have been in his unconscious state. However, the buildup of his character change since the Hashira Training arc, and the portrayal of his character in the recent trailer hints towards his new persona that can be expected against Kaigaku in the Infinity Castle movies.

Furthermore, fans know that Zenitsu is going to be serious when he's going to face Kaigaku, because of their long history. Both Kaigaku and Zenitsu trained under the former Thunder Hashira, Jigoro Kuwajima. Despite both of them sharing animosity, Zenitsu really admired Kaigaku and looked up to him with respect. However, Kaigaku belittled Zenitsu and called him "dirt" for being weak.

While both of them aspired to become Demon Slayers and join the Corps, Zenitsu maintained his goal and did so. Kaigaku, on the other hand, betrayed the Corps and joined the Twelve Kizuki upon being offered a position by Kokushibo. Even after becoming a demon, Kaigaku's hatred towards Zenitsu didn't go down.

Zenitsu's change in aura and personality can be credited to Kaigaku to some extent. His persona change during the Hashira Training arc was purely right after he learned that Kaigaku had joined the Twelve Kizuki. Furthermore, the respect Zenitsu once held for Kaigaku fueled into rage and determination to defeat him.

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Final thoughts

The battle between Zenitsu and Kaigaku has been highly anticipated by both anime and manga fans of the Demon Slayer series. The manga has mostly shown Zenitsu in a cowardly light throughout, but Ufotable is finally doing justice to his character and depicting just how strong he is, after turning a new leaf.

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