The project was a joint effort that featured multiple powers. Each phase required the help of various experts, even if some only had to play a small role in the matter.
Noah had built the landmass' core, but his tasks weren't over. His influence was the only force able to suppress and control his creation, so he had to remain around and watchful.
Emperor had to work closely with Noah due to his unique ability. The landmass would start eating the fabric of space if the expert didn't provide energy. Noah even had to predict whenever his creation would become hungry at some point since the project had reached critical phases.
June, King Elbas, Great Builder, and Divine Demon were the true stars of the project. Their knowledge of the inscription's field was boundless, and their specific fields were necessary for different reasons.