Sauron was the ancestor of wizards, a fallen wise knight who had been stigmatized by the Church. Judging from what he had done to the wizard civilization, he should not be a selfish person. He must have some great intentions for doing all of this.
"Perhaps he's also opening up the path of a knight like me, or searching for other transcendent paths for humans other than wizards..."
These were all Levi's guesses.
He was too far away from Sauron's realm. It was impossible for him to figure out what an existence that could kill a god was thinking.
After returning to the empire, Levi said to the Golden Feathers King, "Golden Feathers, from today onwards, you will lead a team of Feathered People and not let go of any news of the ancient ruins. Go to the ruins to search for a sword-shaped treasure, a lamp-shaped treasure, and a magic mirror, they might be things that can speak," Levi said.