Well at various points in the novel he has concocted pills to strengthen his foundation, so that he wouldn't have to worry about it. For example in the first 10-20 chapters he made some pill with a lion demon if I remember right that strengthened his foundation. Later he made an even stronger pill. It seems like every cultivation realm he's finding stronger and stronger items to reinforce his foundation. What exactly does the foundation mean you may ask, and I'm gonna guess it has something to do with his body or his natural strength without cultivation. Maybe he is strengthening his original dragon marks? Hard to say. As far as him needing comprehension or enlightenment it's a bit funny considering he has the comprehension and enlightenment of the worlds strongest saint already, but since he's cultivating along a new math (Dragon Marks) I can sort of buy that.