I’m Anan Uchiha, and I’ve Become Zenitsu’s Junior Disciple

On the night the Uchiha clan was massacred, Uchiha Anan watched as his family was killed by Root. He awakens the Mangekyo Sharingan and accidentally uses its power to travel to the world of Demon Slayer. While recovering from his injuries, he becomes a student of Kuwajima Jigoro, learns Thunder Breathing, and becomes the junior disciple of the crybaby Zenitsu. At the Demon Slayer Corps' selection, the multi-armed monster, the exam's mini-boss, sees a Fire Style: Fireball Jutsu as tall as a three-story building hurtling toward him and turns tail in terror. Danzo stares at Anan in horror. He never imagined that he couldn't even withstand one of the boy's blows. His ten lives would never be enough. Muzan Kibutsuji looks up as a several-hundred-meter-tall Susanoo comes crashing down. He swallows nervously... Actually, staying in the Infinity Castle isn't so bad. He can always wait another sixty or seventy years. The shinobi world watches Anan's Susanoo. One Thunderclap and Flash later, the sky brightens in an instant. Kaguya is so frightened she flees in terror. That swordsmanship is impossible to block, absolutely impossible to block!