Complex sentence: The show's main baddie, Duke Duralumon is next in line to the throne after Sapphire, and is constantly trying to discredit Sapphire so that he can be the one to inherit the throne.
Split into simpler sentences: The show's main baddie, Duke Duralumon is next in line to the throne after Sapphire. He is constantly trying to discredit Sapphire in order to inherit the throne.