Demon Slayer: Laser Weapon at the Beginning, Saving the Butterfly Ninja

[Start with Infinite City] + [Master Future Technology] + [Rewrite Regrets] + [Happy Ending] + [What are you breathing? Uh... Breath of light? Qin Feng was originally the top scientist of the contemporary era. After developing laser weapons, the laboratory floor tiles under his feet suddenly turned into tatami mats? ! And disappear suddenly? After a moment of dizziness and weightlessness, when I opened my eyes again, I was already standing in an infinitely twisted city! There are human-eating monsters all around! Just when he was desperate, Qin Feng turned his head and suddenly saw the laser weapon hanging beside him! Qin Feng: Although I don't know what's going on, I'm sure. Wuxian: Why did I suddenly feel a terrifying aura... Naruko: It seems that an unknown creature has been teleported to me. It shouldn't be a problem... Just as Qin Feng was looking for his way back, he suddenly saw a pond with lotus flowers, causing him to slowly open the door. But when he walked in, he saw a dying girl wearing a colorful feather coat and a butterfly on her head...