Since successfully establishing his Foundation in Longevity, Chen Mobai has devoted part of his energy to the Pure Yang Scroll.
After all, the cultivation techniques in the Tianhe realm, aren't as detailed in the Foundation Building Realm as they are in the immortal sects.
If he wanted to advance from the early foundation stage to the mid-foundation stage, it would usually take about twenty years according to the experiences in the Tianhe realm.
Given that the breakthrough in the Longevity would take some time, and he still had pill toxicity in his system from the Foundation Building Pill he took during his foundation establishment, Chen Mobai spent most of his time after his foundation establishment on improving his understanding of the Pure Yang Scroll.
Under the vast knowledge of the Foundation Building Realm, he easily and thoroughly mastered the Qi Cultivation part of the Pure Yang Scroll.