The Villain Demon King, Ruling the World

My name is Ammons, and I'm a villain. I can modify common sense and exchange various villainous abilities through the Demon King System to create my own Demon King powers. Reincarnated from ancient times into a useless prince, this holy mage protagonist's magic is unmatched, but your fiancée is too shy~ Your master is very charming~ And there's the genius prodigy from the Duke's family, born invincible, and your sword saint maid is very alluring! What, you're actually a little loli? Well, I'll take you all! Those reincarnated old men, overpowered protagonists, heroes, etc., with me, Ammons, you'll all suffer!