Zenitsu ranked 2nd place in the first popularity poll with 4,299 votes. Zenitsu ranked 1st place in the second popularity poll with 17,451 votes. Zenitsu also appeared in The Promised Neverland's 2020 popularity poll, ranking 29th place with 44 votes.
Unfortunately, the answer to this question would be, no, he did not. Zenitsu, along with Tanjiro and Inosuke got way stronger than average corps members with training. In fact, he became one of the very few to even invent a new form of Thunder Breathing. However, his dream of becoming a Hashira was never realized.
What rank was Zenitsu brother? He was a member of the Twelve Kizuki, holding the position of Upper Rank Six after the deaths of Daki and Gyutaro. He serves as a supporting antagonist in the Infinity Castle Arc.
Inosuke was ranked in 5th place as of the first character popularity poll with 1,977 votes. Inosuke is left-handed. Inosuke doesn't care to remember other peoples names, and usually gets it right every seven attempts (referring to Tanjiro as Gonpachiro, Kentaro, Monjiro, etc.).
Demon Slayers are known for their strength and bravery in battle, but not Zenitsu. Despite his cowardice, he's one of the strongest in the series.
Overall, Zenitsu is an extraordinary powerful Demon Slayer capable of singlehandedly bringing down an Upper Rank, which said to be able to overpower 5 Hashira, in 10 minutes, albeit he would have beheaded Kaigaku in a heartbeat if it wasn't for his feelings of melancholy and pity.
Given how talented Tanjiro is, it's likely he'd defeat Zenitsu, even if the latter could fall asleep and call on his powers. Tanjiro's demonstrated his ability to take down more powerful demons and adapt to training on more than one occasion, so it just makes sense.
She was ranked in 3rd place in the first Demon Slayer character popularity poll with 3,319 votes. IGN regarded Nezuko as one of the series's most popular characters and noted how her design elaborates the way she sees humans as good people as a result of hypnosis.
That being said, Tanjiro's rank is unknown, and his rank was last revealed in the Entertainment District arc. In that arc, they were at Kanoe, which is fourth from the bottom. Since Kiriya Ubuyashiki announced the disbanding of the organization, Tanjiro doesn't get the chance to become a Hashira.
But as fans saw through his training period and taking on increasingly tougher missions following the fight on the Mugen Train, Tanjiro has been rising through the ranks (unbeknownst to himself) and has now risen to the level of Kanoe, the fourth rank from the bottom, along with Inosuke and Zenitsu.
Zenitsu Agatsuma vs Kaigaku is a battle that took place in the Infinity Castle. It focuses on the battle between Zenitsu Agatsuma against Upper Rank Six Kaigaku.
History. Jigoro was the instructor of Zenitsu and Kaigaku as the former Thunder Hashira. Kaigaku managed to master all of the Thunder Breathing Forms except for the first Form, meanwhile Zenitsu had only managed to master the first Form and none of the others due to his inexperience.
So in a nutshell, Zenitsu wasn't able to master the other five forms, but later in the Infinity Castle Arc, during the battle with Kaigaku, Upper-Rank Six Demon, he created a Seventh Form: Flaming Thunder God.
As a result, Tengen Uzui has to deal with the moniker of being the least powerful Hashira around.
Giyu ranked 4th place in the first popularity poll with 2,190 votes. Giyu ranked 2nd place in the second popularity poll with 13,281 votes.
One plot point fans never did get to see was Tanjiro becoming a Hashira. By the time his promotion would've been necessary, the goal of the Demon Slayer Corps was already achieved. However, this doesn't mean Tanjiro wasn't Hashira level by the series' end, or that he couldn't hang with his colleagues if made Hashira.
2) Inosuke
During the Hashira training arc, Inosuke performed exceptionally well. Even Tanjiro needed a few days to pass some parts of the training, while Inosuke seemed to breeze through. His performance against Doma definitely puts him on Hashira's level.
In conclusion, Nezuko cannot beat Akaza in Demon Slayer. In terms of power, physical abilities, regeneration rate and overall combat ability, Akaza is far superior compared to Nezuko.
Upper-Rank Five: Gyokko
Gyokko was one of the Upper-Rank demons who attacked the titular village in Demon Slayer's "Swordsmith Village" arc. Facing off against the Mist Hashira, Muichiro Tokito, Gyokko was the only Upper-Rank in the series who 1v1'd a Hashira and lost.
3) Zenitsu Agatsuma
Zenitsu, with his insane strength and lightning speed, can eliminate every Upper-Rank Demon in 1v1 except Upper Moon 1, and Muzan because in terms of strength they are more formidable than him.
Intimidation alone would allow Giyu to beat Zenitsu in a fight, but it's also obvious that Giyu's combat skills would allow him to crush the other boy based on physical ability alone. Zenitsu has a long way to go before he reaches Giyu's level.
Zenitsu is at least close to Hashira level by the end and Godspeed has limited uses because it disables his legs after those uses. Zenitsu's faster but if this was an actual race or marathon, Shinobu would beat him.