Gyutaro manages to poison Tengen during the fight, preventing him from decapitating the Demon. After they finally manage to bring down the Demon siblings, Tengen ends up losing his left hand and eye in the process.
However, Uzui loses one of his arms and an eye in the fight, leaving Tengen Uzui with no choice but to retire from the Demon Slayer Corps. Also, the manga never specifies how the sound Hashira Tengen Uzui dies in the future, which gets us to the conclusion that he passes away from a natural cause.
Tengen Uzui Retired to Live His Best (Flashiest) Life
Squaring off against Upper-Rank Six, a title shared by demon siblings Daki and Gyutaro, Tengen thankfully survives this encounter -- but just barely.
Tengen received extremely harsh training that killed all his siblings except for his younger brother who became cold and heartless.
Tengen Uzui indeed dies in Demon Slayer, but that happens after the time skip. He survives his nearly fatal encounter with Gyutaro and eventually dies sometime before the final chapter of the manga, i.e., sometime during the large time skip.
By the end of the battle, Gyutaro's poison has spread throughout Tengen's body resulting in his inability to speak. As he lays dying from the poison, Nezuko Kamado intervenes and uses her her Blood Demon Art to burn the poison out of his system, allowing him to rejoice with his wives.
Unfortunately, many fan-favorite characters met brutal, untimely demises in Demon Slayer, and the Hashira certainly weren't an exception. Some of their fates, however, were much sadder than others. On a positive note, none of the Hashira died in the Swordsmith Village arc.
Like most of the characters, Tengen Uzui does have a descendant that looks just like him. His descendant is named Tenma Uzui and he's an Olympic-level gymnast representing Japan.
When it comes to pure strength, Shinobu Kocho is the weakest Hashira in Demon Slayer. She doesn't even have enough strength to decapitate a demon's head and she makes up for it by injecting poison into the demons.
Unfortunately, Gyutaro spots Inosuke and stabs him right through where his heart should be with a sickle imbued with deadly poison.
1 Mitsuri & Obanai
Unfortunately, the Serpent Hashira also succumbed to his injuries. He and Mitsuri confessed their love and died together shortly after. They promised to meet again in their next lives, which they did — their reincarnations run a bakery together.
The demon slayers successfully defeated Muzan.
During the fight, Muzan blinded the Snake Hashira, who continued to injure Muzan despite this handicap. But the valiant young man succumbed to his injuries and died eventually. Moments before dying, the Snake Hashira confessed his feelings for Mitsuri.
Demon Slayer's Tengen Uzui is considered to be one of the weakest Hashira due to almost losing this fight, but the fact is that Tengen only looks weak when compared to the most overpowered Hashira.
Tengen Uzui
He is the fastest Hashira, and the second physically strongest. Obviously, then, Tengen Uzui is rather proud. He is demanding, fussy, boastful, and prone to selfishness. But he is also ultimately kind and caring, with great love for his three wives as well as the other Hashira.
i know, though, some believe he loves hina (21) the most, because he had the most interaction with her in the manga and they have the most “husband-and-wife” feel. we also have to remember that suma (19) was tengen's first chosen wife—they both personally agreed to letting hina and makio (20) into their relationship.
1. Gyomei Himejima – The Stone Hashira.
The Wind Hashira has one of the saddest backstories in Demon Slayer. His mother had turned into a demon and had killed five of his siblings. He was forced to kill his own mother in an attempt to save his only remaining brother, Genya.
Suma ( 須 す 磨 ま , Suma?) is a supporting character of Demon Slayer: Kimetsu no Yaiba. She is a kunoichi and one of Tengen Uzui's wives.
Trivia. Makio is actually a distant cousin of Tengen's.
Tengen Uzui (宇髄 天元) is a major protagonist in the 2016-2020 fantasy horror manga series Demon Slayer: Kimetsu no Yaiba and its 2019 anime series adaptation. He serves as the deuteragonist of the Entertainment District Arc and the season 2 anime adaptation. Tengen is the Sound Pillar of the Demon Slayer Corps.
Demon Life
At some point, Daki fought, killed and ate seven Hashira. Two days before Tanjiro Kamado and company infiltrated the Entertainment District, Daki was confronted by Omitsu, the manager of the Kyogoku House, over her mistreatment of the staff.
During Tanjiro and the rest of the Hashiras' showdown with the Demon King Muzan, Tanjiro is mortally wounded and dies. At the same time, Muzan receives a particularly fatal lil' booboo himself. As Muzan is about to shuffle off the mortal coil, he uses the last of his powers to turn Tanjiro into a demon.
Tanjiro decapitates Akaza with the Hinokami Kagura: Setting Sun Transformation. Akaza was bewildered, wondering how Tanjiro did not have any fighting spirit, comparing this feeling to fighting against a plant. He acknowledges that Tanjiro surpassed his speed.