In the "Entertainment District" arc of Demon Slayer, the flamboyant Sound Hashira Tengen Uzui was pushed to the limit during his conflict with the demon twins Gyutaro and Daki of Upper Moon Six. The action sequences in Tengen reminded me of the stunning swordsmanship displayed by Hashira in Demon Slayer: Mugen Train: Kyojuro Rengoku thanks to the movie-level animation quality.
Rengoku's influence and impact on the Demon Slayer cast and fanbase are still felt even after his death. The Flame Hashira radiated kindness, power, and self-sacrifice, making him beloved by all who wished for more of the great Rengoku. What if he had survived his encounter with Akaza and taken Tengen's place as the main Hashira in the Entertainment District? Specifically, how would Rengoku fare in a fight against Gyutaro and Daki in comparison to Tengen?
The Benefits of Rengoku Over Tengen in Demon Slayer
Even his Demon Slayer peers thought highly of Rengoku as one of the best Hashira. Tengen Uzui is one of Rengoku's most ardent supporters, lamenting that "even Rengoku couldn't defeat an Upper Moon" and addressing Rengoku's spirit for guidance at the conclusion of Season 2, Episode 15.
Rengoku was a master of Flame Breathing techniques and a physical beast who could match wits with the most potent demons in the series thanks to his natural talent and birth into a long line of Flame Breathing masters. While the two engaged in their epic battle, Akaza would frequently compliment Rengoku's reflexes and speed. Tanjiro was unable to keep up with their movements.
Tengen was a combat expert in his own right, with his dual Nichirin blades and explosives bag, but Tengen's feeling of inferiority to Rengoku demonstrates just how incredible the Flame Hashira was. Rengoku dominated Upper Moon Three Akaza on his own, while Tengen barely escaped with his life against Upper Moon Six despite the assistance of Tanjiro, Zenitsu, and Inosuke. Rengoku, with his superior speed and diverse arsenal of multipurpose breathing techniques, would likely outperform even Tengen in defending himself against Gyutaro and Daki's barrage of attacks.
Reasons Rengoku Would Ultimately Lose to Gyutaro and Daki and His Drawbacks
Tengen's physical advantages and special Musical Score Technique made him the ideal Hashira to face Gyutaro, even though Rengoku might have an edge over him in terms of raw combat prowess. Even after losing an arm, he was able to read Gyutaro's movements perfectly and counter them thanks to his Musical Score Technique and the poison resistance he had developed through his shinobi training.
Rengoku's defense would have to be flawless without poison resistance, which would be nearly impossible given that he would also have to fend off Gyutaro's blinding speed and Daki's hordes of Obi. Tengen had access to a second blade as well as explosives, which he used to strengthen his defense. With just his sword as protection, Rengoku would have even less room for error.
There is a chance that Rengoku could defeat Gyutaro and Daki using his skill with a sword and his mastery of breathing if he were given the same support that Tengen received from a relentless Tanjiro, Zenitsu, and Inosuke. Tengen, on the other hand, was the specifically better matchup to deal with Gyutaro's poison blades; even if Rengoku managed to secure a victory, he would probably die in the process, making for a grisly scene that Demon Slayer fans wouldn't want to relive.