Demon Slayer: Why Is My Ripple Breathing Not Considered a Breathing Method?

[JOJO + Demon Slayer + Er Qiao + Funny Sand Sculpture + Self-Created Stand + Void (Yes, similar to Kamui Void)] Note: This book enters the main plot after Chapter 5. Since the author is a novice, he may modify the chapters or add some in the middle. When Xia Yu, a college student, was chasing Demon Slayer in his dormitory, his old robot suddenly exploded while he was looking good. So Xia Yu, thinking, "Now his cheap roommate is going to be admitted to graduate school," traveled to Demon Slayer's world. Xia Yu has no system and has not become a character in the original work. He is worried and feels that his future is gloomy with a grimace. But at this moment, purple vines crawl out of his hands. … "Keep an eye on him~ The attack is flawless~ Want to hide? Hehe~ Come on, let me, Nostalgia! The Purple Requiem of the Hermit! My stand-in is the most useful!" "No misfortune! Come out to bask in the sun! What? You don't want to bask in the sun? You have to bask in the sun even if you don't want to bask in the sun! Watch the trick! Ripple Breathing Technique! Ripple Walk!!" Wuxian: "... You are a hook!"