It's impossible for him to normally advance within the Mechanical Divine Sect.
Duncan could still muddle through in the early days, but in the future, as his strength grows, sooner or later he will have to go to the Holy Temple of the Mechanical Divine Sect for further training. By then, even if he's under the eyes of the Guardian Angels, he might be detected by the Insight Angels on some day.
His current plan is to first secretly strengthen his own ranks, find a way to infiltrate the Mechanical Divine Sect, and steal the technological knowledge of this era as a form of resource reserve.
This way, even if his Number 3 Human Form is lost some day, he won't be at a loss.
The technological knowledge Duncan can steal at the current stage is limited, barely enough for the First Industrial Revolution. As for the subsequent technological iterations and cross-era technological reserves, he will have to find ways from the technical cultivators of the Mechanical Divine Sect.
