In the end, the devil in stories, novels or anime is generally a very tragic existence.
"Feiyou, shut up. I, Tinkeri, will definitely go back and defeat that hateful hero."
Sadly, Tinkeri Yarisarana has never been able to defeat the hero. She only blames herself for sending too many monsters, causing the hero to have MAX times more experience than herself, and was forced to come to Japan from Shusura Continent. Wonderful stories happen.
However, the premise of the story is strange. A certain demon king and her servants still have to make money in order to live well in this different world where the prices are beyond the acceptable level.