Mu Dan had a calm and carefree attitude, as he usually carried around a smile on his face, while having a blunt way of speaking. Under his carefree demeanor, Mu Dan possessed a cruel and sadistic personality towards humans, as Tao Fa noted that he was well-known within Lord Tensen for his love of toying with the race.  While the main goal of Lord Tensen is to extract Tao from humans to create Tan, Mu Dan took the group's complete disregard for human life a step further by modifying the humans.