Based on Su Chen's conjecture, he believed he should be able to refine Weiji Pill. As for how many grades it could elevate, he was not yet certain. After all, this was the Immortal Realm, not the Tianhuang Continent; due to the plane's level restrictions, refining Weiji Pill might allow him to break through by three grades.
To refine Weiji Pill, he probably needed his cultivation to break through to the Immortal Realm, or at least have his Primordial Spirit advance to the Immortal Realm first. Unfortunately, he had just recently broken through to the so-called Void Saint Realm.
Most importantly, he needed more time to comprehend the so-called Three Thousand Dao of Alchemy.
Chapter 539