Traveling Through Multiple Realms: The Supporting Character's Counterattack

In the Naruto world, he is Genma Shiranui, the inheritor of one-third of the Flying Thunder God Technique, the Konoha King, and the Hokage's bodyguard; in the One Piece world, he is King, the last surviving member of the Lunaria clan and the leader of the Three Disasters of the Beast Pirates; in the One-Punch Man world, he is Iaian, the second-ranked A-class hero and the top disciple of Atomic Samurai... In short, this is the story of a handsome young man from Earth who stumbles upon a stroke of luck, simultaneously transmigrating into various supporting characters across different worlds, and then rising to prominence in each world through his own efforts.