Duan Ling Tian was naturally touched by Yang Yu Chen's words. However, he was unwilling to accept Yang Yu Chen's suggestion since he knew Yang Yu Chen's true body would be affected to a certain extent if he sent his doppelganger out. He knew this very well since he also had experience in using doppelgangers.
When controlling doppelgangers, one could go on with life as usual, but one would still need to keep a part of one's mind to control them. Unless one's doppelganger was inactive, one would not be able to fully focus. Usually, Duan Ling Tian's doppelgangers would be inactive when he was immersed in cultivating.
