Martian's manga / #Martial Arts(2)

Okay, need to explain to future self. Mc was originally yun and abused mu, then he became mu 10 years in the past and became a doctor which mu hadn’t been, then after ten years at same moment switched back. Original mu had spent 250 years in other world with magic in meanwhile and now returned. Yun’s soul is damaged, was before the switch, and mu is helping him repair it you know what makes that process easier.