'I wonder whether I can stay in this world longer and peacefully complete the Re: World Assessment.'
Even though Leo had become the partial [World Emperor], he was not sure whether he could stay in this world as long as he wanted.
'Should I ask the Ancient Beast about it?'
Leo thought of asking the Ancient Beast because it seemed more knowledgeable than him and the system.
'Also, does this world not have any Ancient God who looks after it?'
As far as what Leo learned about the World Grades and the World Assessment so far, there will be a [World Emperor], [World God] and the [Ancient God].
A [World Emperor] will manage the natives of the world.
A [World God] will bless the [World Emperor] and his subordinates from time to time depending on their achievements.
Also, he would be in charge of developing the world by providing special energies such that more powerful natives would be born in the world.