
Eightfold ( 八 ( はち ) 連 ( れん ), Hachiren ?) - An extension of the Thunderclap and Flash technique created by Zenitsu. The user performs Thunderclap and Flash six times in quick succession while slightly augmenting the power and speed of his dashes. Sixfold ( 六 ( ろく ) 連 ( れん ), Rokuren ?) - An extension of the Thunderclap and Flash technique created by Zenitsu. This technique is extremely reminiscent of Iaijutsu and its movements are described to be akin to "lightning ripping through the air". First Form: Thunderclap and Flash ( 壱 ( いち ) ノ 型 ( かた ) 霹 ( へき ) 靂 ( れき ) 一 ( いっ ) 閃 ( せん ), Ichi no kata: Hekireki Issen ?) - The user unsheathes their katana, dashes forward at blinding speeds and decapitates their opponent faster than they can react, before sheathing it back. Thus, it is currently unknown how a normal swordsman would perform these techniques. Note: Since the second to sixth form has only been displayed by Kaigaku who uses lightning in conjunction with his swordsmanship. 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 Breathing has 6 standard forms in total, with the first form said to be the foundation for all the other forms. Ī known cultivator of Thunder Breathing in the Demon Slayer Corps is the former Thunder Hashira, Jigoro Kuwajima. This Breathing Style was created from one of Yoriichi Tsugikuni's students who attempted to learn Sun Breathing, but due to not being as innately powerful as Yoriichi, they were instead taught an alternated personalized Breathing Style that focused on their individual strengths and weaknesses, which eventually evolved into Thunder Breathing. This Breathing Style is also very reminiscent of a swordsmanship style practiced and utilized in real life known as Iaijutsu, a famous quick-draw sword technique.
Users also mimic lightning to such high fidelity that they cause the air to vibrate when poised to unleash a technique and create immensely loud sounds akin to thunder with their mere footsteps.
It has been remarked by Zenitsu Agatsuma that this Breathing Style focuses on channeling strength into the user's legs, and maximizing the output of every single muscle and blood vessel in them. Users of Thunder Breathing also visualize themselves seemingly creating and manipulating lightning and electricity when unleashing its techniques. Most, if not all, known techniques and forms involve utilizing blinding speeds and immensely fast attacks to overwhelm the enemy in an instant. Thunder Breathing is a Breathing Style that mimics lightning, specifically swift strikes and movements akin to lightning ripping through the sky, and replicates it with the user's movements, techniques and abilities.