There are six forms, but Zenitsu could only learn the first form said to be the basis for the others yet he honed it to where he could fight against several strong demons. He later created a seventh form and defeated his former senior who had become the Upper Rank Six of the Twelve Kizuki.
Though he's on a journey to get over his fears and wants to be a better version of himself. However, as every Demon Slayer affiliated with a Breathing Style develops certain forms which give them an advantage in combat, Zenitsu could only learn the first form of Thunder Breathing: Thunderclap and Flash.
Thunder Breathing has 6 standard forms in total, with the first form said to be the foundation for all the other forms. However, Zenitsu Agatsuma developed a Seventh Form in order to stand on equal ground with Kaigaku, his former senior disciple under Jigoro who had become the Upper Rank Six of the Twelve Kizuki.
Thunder Clap and Flash—Godspeed is the most powerful of Zenitsu's derivations of the Thunder Breathing first-form technique.
172.1 Km/h Whenever he performs his thunderclap And flash move.
Tanjiro isn't Faster Than Zenitsu, not at all. He is Strong but Slow. So, Zenitsu Will Probably Chop Him Down to bits before tanjiro even pulls out his sword properly. There ya go!
But, comparing the two characters in their best forms, Zenitsu might be just a tad bit faster owing to his Godspeed move.
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.
At this point Zenitsu has manifested his speed and power, and he was also able to keep up with the Demon King, Muzan, even when weakened. It's possible to say that his power easily matched the strength of a Hashira.
Zenitsu is clearly on the same level as Hashira. If we compare him to Shinobu, his speed is far better, while she lacks quite a lot in raw power. There is a good chance that he could beat Shinobu if the two decide to fight.
Zenitsu was even able to exert himself for around half an hour during the fight against Muzan, even being able to surpass his limit of only being able to use his Thunderclap and Flash: Godspeed technique twice a day before his legs gave out.
To sum it up, it is possible for Zenitsu to fight without fainting and it has been shown clearly in the manga. While he only perfected the first form, he trained hard enough to create a new form that didn't exist before.
Thunder Breathing is one such technique that Zenitsu has used to great effect in the series. Of course, Zenitsu is only the master of the first form, but it goes without saying that the other techniques of Thunder Breathing will also be awe-inspiring to witness in Demon Slayer.
Unfortunately, he retired at the age of 35, when he lost his right leg in a fight with a demon. Since then, he devoted his time to teaching the next generation of demon slayers, most notably, Zenitsu Agatsuma, who lovingly called him "grandpa".
The eccentric and flamboyant Tengen Uzui is the current Sound Hashira. This Breathing Technique gives him echolocation and other advanced hearing abilities.
Zenitsu is an incredibly powerful Demon Slayer, but he's always in fear. His nerves calm down when he's asleep, so that's when he awakens his “powers”. MANGA SPOILER AHEAD!!!
2) Tanjiro Kamado
With Sun Breathing, which is regarded as the paramount of all Breathing Styles, Zenitsu will have a hard time subduing Tanjiro and will be defeated by the latter in no time.
Gyomei Himejima, the Stone Hashira, is the strongest Hashira in the Demon Slayer corps in terms of strength and swordsmanship. He is the only person who uses spiked flails and an axe instead of standard swords to kill demons. Such a weapon takes immense precision and soundness to use without inflicting personal damage.
1. Nezuko. Nezuko, also a part of our strongest characters in the Demon Slayer list, is one of the most powerful female characters in the anime. Just by being a demon, she is more powerful than all the human characters in the series.
slow ?! , Deku was able to dodge and hit in a split second. And yet he is clearly faster than Zenitsu .
Comparing Zenitsu before his stay at the Butterfly Estate to Kanao, we'd probably guess that Kanao would defeat him easily in a one-on-one match. But after Tanjiro, Zenitsu, and Inosuke train with Kanao and the others residing at the estate, Zenitsu manages to best her — in terms of speed, at least.