Out of everyone, Asileius was the only one who could help Matthias because of his innate power of comprehending creation.
A lot, especially Bai Changsheng, discovered and realized a lot while watching them create the realm. Although they cannot fully comprehend the depths of creation, just the glimpse of that power made them feel insignificant and unimportant. The feeling of powerlessness welled-up on them.
They discovered that they aren't even close to the peak of power, and that they aren't even as important as a grain of sand beyond the vast universe.
They comprehended a miniscule part of the lower laws of creation, a mix of Chaos, Order, Dao, and Space inside one law.
Through that comprehension, Bai Changsheng deduced laws and techniques to cultivate and become a deity who could theoretically tinker with creation.
Later on, because of an event, one man will rise to prominence because of the technique that Changsheng created. But that will be a story of a later age.