Mao Siyue: Taking Over the Pope of Light's Body from the Start

[My Four Months with Four Cats and the Legend of the Elves fanfiction + soul transmigration into a villain + System + no female lead + building a faction + ensemble cast + the Myriad Worlds] A modern person from Blue Star accidentally transmigrates into the world of My Four Months with Four Cats and the Legend of the Elves, taking over the body of the ultimate villain, the Holy Pope of Light, and gaining the Myriad Worlds Faction-Building System. The story begins several years before the original plot. The first demon-purge campaign has yet to begin, and the continent's greatest prodigies are the Empire's Twin Stars of a bygone era. This time, everyone's fate will be completely rewritten, and he will utterly transform the balance of power across the continent...