In this respect, Fan Tie was a very clear case. Even though he disguised himself well, Qi Tian was still able to see through his camouflage using the Heavenly Dao Engine and knew that he and the cultivators of the Great Zhao Nation were not on the same side.
Qi Tian felt that if Fan Tie wanted to lurk in the County Master Mansion, there were some things he definitely wouldn't conveniently take care of himself and would certainly need to support one or two proxies. These proxies might be taught the cultivation methods of Fan Tie's world by him, and once they practiced, the fluctuations of Spirit Force on them could be very different from those of the other cultivators of the Great Zhao Nation. At that time, Qi Tian could easily distinguish them from other cultivators.