The Fallen Knight Who Lives Beside the Saint

[Western fantasy + hegemony + fast pace + multi-race + system + multiple female protagonists] The righteous saint of the Holy Empire, protects the family and the country, and eliminates evil in the right way Suddenly one day, the saint who swore to protect all turned her sword around and used blood and fire to completely destroy the empire and the church. Noble: "Why is this saint more ruthless than the devil?" Emperor: "Who told her?" Pope: "I can't come!" Demon King: "This has finished my work, what should I do?" God: "Quick! Fight quickly! Let's all fight! I want to see rivers of blood flowing!" (The plot is a bit dark, so don't go into it if you don't like it)