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.
Enhanced Strength: Zenitsu has attained amazing physical strength through years of harsh training.
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.
While Zenitsu has low self-esteem and he's afraid of fighting demons, he also ends up being one of the strongest characters in the series. However, he needs to lose consciousness to use his real strength. This is way Zenitsu is always with his eyes closed while in battle.
Final Thoughts. Clearly, Tanjiro is much stronger than Zenitsu in Demon Slayer. Tanjiro beats Zenitsu in every relevant category to the question, whether fans directly see this or it's implied. The unique powers of Demon Slayer would normally make it difficult to power scale and compare two characters.
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.
When facing Kaigaku during the Infinity Castle arc, Zenitsu debuts his brand new exclusive Seventh Form to Thunder Breathing. With this, Zenitsu finally has more than one tool in his arsenal and has overcome his own personal doubts and fears.
If he could, Rengoku would win simply because Zenitsu cannot perform Godspeed more than twice. Since Zenitsu only knows the first form, Rengoku would know what to expect and accordingly counter his moves, taking him down in the end.
Inosuke always displayed raw strength and courage from the first few chapters of Demon Slayer. One might even argue that he was far stronger than Zenitsu during the first arc.
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.
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.
Zenitsu's rankings in the popularity polls are as follows: 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.
Exploring Zenitsu's fighting abilities in Demon Slayer
Zenitsu has perfected the first form only and is seen performing it only when he's unconscious. But the manga shows that he can fight without fainting or going unconscious.
This wasn't the case with Zenitsu, whose mastery of Thunderclap and Flash is clear for everyone to see. This mastery allowed Zenitsu to form a Seventh Form of Thunder Breathing that is unique only to him: Honoikazuchi no Kami.
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.
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.
Which Hashira can beat Tanjiro? Going beyond this, Giyu is one of the most combat proficient Demon Slayers seen throughout the entire series. Furthermore, his strength and abilities are always portrayed as seemingly a cut above the rest of the Hashira, solidifying his expected victory against Tanjiro.
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.
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.
Zenitsu, while awake, is aware of his surroundings, and can sense demons quite efficiently with his 'Enhanced Sense of Hearing', but when it comes to even slight contact with a demon, he blacks out. So, to sum it up, his fear of going against terrifying demons that could end his life, drives him to fall asleep.
9/10 Zenitsu Agatsuma Swiftly Defeated Kaigaku With A New Technique. Kaigaku was originally a disciple of Jigoro Kuwajima along with Zenitsu.
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.
Unfortunately manifesting his Mark in the battle against Akaza also doomed Giyu to die by his 25th birthday, taking the air out of his survival.
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.