In the 17th episode of , titled "You Must Master a Single Thing," the story focuses heavily on Zenitsu Agatsuma's character development and his battle against a terrifying spider demon on Mt. Natagumo. ⚡ Episode Summary
While Tanjiro and Inosuke push deeper into the forest, Zenitsu finds himself alone and surrounded by smaller spiders with human heads. He eventually encounters the "Son" of the Spider Family, a demon with a giant spider body and a human head, who reveals that Zenitsu has been bitten and will transform into a spider in 30 minutes. Key Backstory & Power Kimetsu no Yaiba Episode 17
The episode features a pivotal flashback to Zenitsu’s training under his master, whom he calls "Gramps". In the 17th episode of , titled "You
In a moment of extreme fear, Zenitsu falls into a deep sleep/trance and unleashes Thunder Breathing, First Form: Thunderclap and Flash, Six Fold , decapitating the demon in an instant. He eventually encounters the "Son" of the Spider
Zenitsu was often a coward and once hid in a tree to avoid training, only to be struck by lightning, which turned his hair yellow.
Zenitsu was only able to learn the First Form of Thunder Breathing. His master taught him that if he could only do one thing, he should "hone it to perfection" until it becomes a supreme strike.