Ah that ending. If that's the case then Yutarama was the source that of that evil mana Takiya, the king, and the party defeated. Guess it wasn't just some nameless one off demon king.
Unsatisfying? This is a very basic learning to forgive and move on chapter and it did its job well enough even if I myself felt like it could've been 2 chapters. You're looking for gold in a sand box.