Within the Cultivation World that Wei Cheng belongs to.
Old Zeng had just completed the cultivation of the Fourth Primordial Spirit Armor. This step was still quite easy for him as he had already gone through it in his previous life, but now he was considering whether to cultivate the Fifth Primordial Spirit Armor and the Primordial Spirit World or not.
This was a very, very important decision, of utmost importance, and a key point.
Even in the Immortal World, it is taken extremely seriously.
The Fifth Primordial Spirit Armor is not merely the peak of the Primordial Spirit but can also cultivate the Primordial Spirit World, which is equivalent to reenacting a whole Cultivation World, so complex.
Therefore, it requires massive resources upfront and a great deal of the Power of the Primordial Spirit as well.