Ye Xiao had seen how Heavens and Heavenly Pearl came into being when he broke through to the Immortal Foundation Realm.
He clearly saw the evolution of both Universes. He saw how they evolved from nothing but just a small white dot of light to the current Universe. He saw how Heavens gave birth to the Nine Ancestral Dragons and Queen of Plants.
At first, Ye Xiao only wanted to recreate his Small World but the moment he heard about the Yin and Yang Energies, the idea of forming the Universe instead of a Small World popped up in his mind.
Before, it was not possible but with the help of Yin and Yang Energies, there was at least a 30% chance to successfully form a Universe instead of just a Small World.
Although 30% was a really very low mark of probability, in Ye Xiao's eyes, it was still worth taking the risk.