A Demon King's half-dragon Son is being left to his own devices

Hi everyone, thanks for looking at this. Let me start with there won't be some kind of system, and this isn't a story about a reincarnated protagonist. It's a fantasy story about a half demon, half dragon prince being "kicked" out of Hell so he can find his purpose. Later on, he'll find an abandoned castle, and make a kingdom that protects those who can't protect themselves. That will be his purpose. He will have a harem, but I only plan for 5 members as of June 28th, 2023, the day I made this.