This whole dilemma feels so forced; even though it's been explained, we've been shown so little reason to be sympathetic to the demons that it's hard to even side with the actual shonen manga protagonist. Emma says "our friends like Musica," but Musica's literally just about the only demon anybody's ever had a positive experience with. Meanwhile, we're supposed to feel like Norman is wrong because he's "changed."
I was expecting a more nuanced exploration of the ethical considerations involved in dealing with hostile and alien, yet sentient, beings, and the idea of coming to an understanding with demons despite their monstrous appearances and hostility to human liberty, but any hope of artful discussion has just been jammed down our throats over the last few chapters. Then again, I guess that's average shonen manga for you.