Who Still Has a Career After Becoming a Devil?

As the Demon King, I thought I was responsible for revitalizing the Demon Clan, but the Demon Clan has all perished. The brave human beings are eyeing me, the fate of death is approaching step by step, and the weak demon king is trembling. Your Highness the Princess! Please believe me, these elves, beast mothers, succubi, dragon girls and I are all pure friends! Zhou Yu owns a Demon King's City, and as long as he has enough magic power, he can summon unlimited monsters. Magic schools, adventurers' guilds, dungeons... Why do I build these, you ask? That's of course because they can make a lot of money!