As a member of the Upper-Rank Six, Daki was extremely powerful. She was much more powerful than the regular demons. Her physical abilities were on a completely different level in comparison to some demons that Tanjiro and co. had faced. Daki was immune to decapitation when her brother was attached to her core.
Nezuko is at least stronger than Daki, meaning that if Muzan could bring her back under his control, she would certainly qualify for the most prestigious title a demon can hold: a member of the Twelve Kizuki. Thanks to Nezuko's remarkable strength, she would have to be an Upper-Moon.
It's no question that Gyutaro was the strongest of this sibling duo, but Daki's abilities were nothing to scoff at.
After becoming a Demon Daki grew strong enough to kill and eat seven Pillars and gained the attention of Muzan Kibutsuji who allowed them to join the Twelve Demon Moons. She later dies after being beheaded by Zenitsu Agatsuma and Inosuke Hashibira.
Shinobu v.s Daki: Upper Rank 6
However, Shinobu is too weak to cut off a demon's head, and she can't even behead a demon that isn't a member of the Twelve Kizuki. Daki would most likely be able to hold her grounds against Shinobu in battle, and Shinobu may be worn out.
As a result, Tengen Uzui has to deal with the moniker of being the least powerful Hashira around. Of course, that's not the worst thing in the world, as all Hashira are strong. He's still incredibly powerful and can give any demon a run for their money.
Akaza's rank is far superior to that of the Gyutaro and Daki, and an upper-rank demon is more powerful than the demons with a lower rank. That said, this fight will be two against one. In order to mark his victory, Akaza has to defeat both the sibling demons which can be a bit hard.
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.
The Upper Moon 6, a cruel demoness named Daki, may have lost to Tanjiro and Tengen in the end, but she could defeat a wide variety of heroes from other anime if they tried to slay her.
As a member of the Upper-Rank Six, Daki was extremely powerful. She was much more powerful than the regular demons. Her physical abilities were on a completely different level in comparison to some demons that Tanjiro and co. had faced. Daki was immune to decapitation when her brother was attached to her core.
With that said, all Hashira in Demon Slayer have one glaring flaw: they're only human. As such, they're not infallible and are certainly not tougher than their demon enemies. This results in some rather lopsided matches and emotionally-charged oversights on their part.
Fortunately, Zenitsu was able to single handedly beat the Upper Moon 6. Not only did he defeat the demon, he also created a seventh form called the Flaming Thunder God. These are the demons who have been given the title of Upper Moon 6 in Demon Slayer.
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.
Which Hashira can beat Nezuko? The Wind Hashira is one of the strongest Hashiras in the Demon Slayer series. He played a significant role in defeating Kokushibo and was able to inflict damage on Muzan. Sanemi's sheer power and speed will be able to overwhelm Nezuko even in her final form.
Sound Hashira
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.
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.
Nezuko setting Tengen on fire. 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.
DakiTan is the ship between Daki and Tanjiro Kamado.
Daki/Ume was offered the chance to go to heaven presumably because she didn't choose to become a demon, and she was only 13 when she turned.
Daki views Inosuke as an annoyance, due to him breaking into her food locker and releasing the stored humans she intended to eat.
Rengoku's fight in the Mugen Train arc showed his incredible speed and reflexes. He was able to match Akaza's speed, and his movements were so fast that it was almost impossible for the naked eye to keep up. Tengen, meanwhile, is the fastest runner out of all the Hashira.
While Mist Breathing has six forms, he created a Seventh Form: Obscuring Clouds during the fight with an Upper Rank Demon. Muichiro can defeat Akaza easily with his petite body that leverages his speed. Moreover, his ability of Transparent World can aid him in landing a fatal blow on Akaza's weak spot.
So to cut a long story short, Kyojuro Rengoku is more powerful than Tengen Uzui. Among the Demon Slayer Corps, Kyojuro was acclaimed as a skilled combatant who was always dedicated to fulfilling his duty as a Hashira. Tengen admires and respects Kyojuro for his dedication to protecting human lives.