Actually, apart from his cultivation level,
Lu Changsheng acquired his knowledge in other areas, such as the Dao of alchemy, array formations, talismans, and weapon refinement, through his own self-learning.
He didn't rely on anyone's teaching along the way.
Similarly, he didn't use the system's abilities either.
One day later, outside the library,
Mo Hanlin, all the elders, and Mo Yu were waiting outside.
"Even for a powerhouse of his caliber, it's still too soon to expect him to have read through all those books and committed them to memory, not to mention fully understanding and integrating that knowledge in such a short amount of time," one of them mused.
"Indeed, even for the most fundamental stuff, even with a talent for the Puppet Skill, you would need one or two years to completely grasp it," another added.