For instance, the first decline is "appearance." If one is not careful, one can suddenly age a lot, even with a damaged appearance and a significant change in temperament and form.
This is something female cultivators cannot accept.
Which woman doesn't love beauty?
Even if they are female cultivators, they are still very vain.
According to Sect Leader Aunt, the ancestor of the East Family looked exceptionally young before experiencing the five declines of heaven and man, appearing to be only in his thirties, with quite a bit of the charm of a handsome young master.
Although he couldn't compare to Qin Changqing, he was a handsome man.
However, the last time Qin Changqing saw him, he looked incredibly old. This is the after-effect brought by the first decline.
Moreover, it is irreversible.
Even if you nourish it daily with True Origin, or use some rare heavenly and earthly treasures, you can't reverse it after the first decline.