In Monarch of Magic, you, as the main character, will kill the demon king. After killing him, you'll find a magic gem that can be used to control minds. You can also enslave people and corrupt them as well. Everything you do leads you to take over the kingdom. The task isn't easy, and it's a lofty goal that most people wouldn't be able to achieve. Keep your eye on the end goal, and never allow yourself to deviate for a split second.