With the Grand Tutor's proud and aloof temperament, she would rather suffer a Qi deviation than ever cultivate a Cauldron to help herself achieve momentum through Yin and Yang.
The first time she engaged in dual cultivation with Lu Bei, it was simply because her body betrayed her. The Greater Yang Momentum could not bear the temptation of the Taiyin Killing Momentum Dao, which was how Lu Bei had so easily succeeded.
Even after things naturally fell into place, she had never abandoned the possibility of achieving momentum on her own. If Innate Qi were not inextricably linked to longevity, Lu Bei would never have been able to enter and leave her quiet chamber time and time again.
Chapter 694