Chainsaw Man lives and dies by its mystery. While its gruesome action and dark comedic elements might have made it the household name it's become, narrative has always reigned supreme in of what makes the series chug along. The universally acclaimed Public Safety Saga, or Part One, misdirected the audience's focus onto a Gun Devil that was never actually the main villain, while the events of the meticulously crafted Part Two have all been controlled by the invisible hand of the Death Devil.

At no time is Chainsaw Man willing to over share its secrets with the audience, and that helps to keep readers engaged and in suspense of what may or may not be around the corner. However, while all focus continues to be held on the Death Devil and the apocalypse set to follow in her wake, another villain has openly operated in the spotlight throughout the entirety of Part Two. Yoru, the War Devil, is arguably Denji's biggest threat, yet her behavior and her stated goal of taking revenge on Chainsaw Man don't exactly align.

Throughout recent events, with the titular Hero of Hell within a finger's length of her at nearly all times, Yoru has displayed a bit of hesitance in taking retribution on Denji. The reason why has yet to be explicitly stated in the series, though a theory has begun to take over the fan base that might just be the key to unlocking all of Chainsaw Man Part Two's secrets. And standing tall at the center of the mystery is the War Devil.

Major Chainsaw Man Theory Calls Back to a Cult Classic Movie

Asa and Yoru Are at the Center of the Chainsaw Man "Fight Club Theory"

The Chainsaw Man community is incredibly active, and has been since well before Part One came to a close in 2020. With each new chapter released, countless fans contribute theories about and analysis of the recent events in the series. When Part Two began back in July 2022, fans were caught off-guard when their usual hero was nowhere to be found, and a new protagonist was in his place. Asa Mitaka introduced herself to the manga reading community and immediately became a character adored by many.

It was also around this time that a few fans began spreading the "Fight Club theory". Based on the 1999 David Fincher-directed movie, the theory borrows from its narrator and his more daring and free other half, Tyler Durden. The two are presented as separate characters throughout the film, but are finally revealed to be two halves of the singular protagonist during the final act. With regard to Chainsaw Man, the theory effectively places Asa and Yoru in the roles of the narrator and Durden.

Early on in Part Two, Yoru explains that Chainsaw Man ate from her body, weakening her. When Pochita first appears in the series, he's badly injured, and reduced to his iconic small orange dog form. It can be inferred that their fight in Hell was brutal, and the theory poses that if the War Devil was injured badly enough, there's a chance she either forgot who she was or unknowingly created a fake persona while near death. That would be Asa Mitaka.

The Fight Club Theory Is Out There, But Just Might Work

The Theory Is In Line With Chainsaw Man Part Two's Major Themes

The Fight Club theory may seem a bit out there, but it can work to explain Yoru's hesitance in killing Denji and turning him into a weapon, as well as what seems to be both Asa and Yoru slowly inheriting each other's traits. One of the major themes of Part Two is the sort of gray area between devil and human. Asa points this out when wondering whether to approach Denji, and the tree-hugging guy from the Aging Devil arc calls Denji a devil while he was still very much in his human form.

The series has clearly explored this gray area with its protagonist, but having Asa be the true War Devil while the fan base is predicting Denji will abandon his humanity would be a superb subversion of expectations. If this were the case, it's possible that Asa, while nearly dead during the opening chapter, didn't give half of her brain to Yoru, but rather allowed some of her original War Devil personality to awaken in order to protect herself.

With the name Asa meaning morning in Japanese, and Yoru meaning night, it would make sense that the two are simply alternate personalities of the same person. It wouldn't be the first time a name has been a play on words either, as creator Tatsuki Fujimoto revealed that he named Makima as a play on 'mama', to represent a maternal figure. Of course, Asa was shown to have had a family, which creates a bit of trouble for the theory. However, it's possible she wasn't born to them, and rather was taken in or adopted as the War Devil.

Chainsaw Man Is Approaching Its End Game in the Lead-Up to the Reze Arc Movie

2025 Should Be a Big Year For Chainsaw Man Fans

With the Death Devil established and on the scene, it's likely Chainsaw Man is approaching its end game. However, given the War Devil's immense strength, there's a strong possibility that Fujimoto has once again set up a villain that won't be the Part's final foe, as he did with the Gun Devil and Makima in Part One. Denji will likely have to contend with Asa and Yoru, and if the Fight Club theory proves to be true, the final battle won't be pretty.

A good ending would involve Yoru giving in to Asa's personality, and the War Devil turning a new leaf. However, both Tatsuki Fujimoto and Chainsaw Man have proven time and again that not every character is awarded a happy ending. The Reze Arc film arrives in theaters on October 29th, and it seems the manga is ready to kick up the action in the build-up to its finale. 2025 is shaping up to be a good year for Chainsaw Man fans, and if the Fight Club theory is proven true, everything they know about Part Two will change.