@Psychronia The writing does make sense if you forget about the otome game part. The prince is taking over her business so he change the plan to be done for the royal family and his family neglects the demon king even though he's family. He doesn't seem that good of a person in the first place...
So to clarify things, he's in the fantasy muitiplayer rpg he created and deleted. He created a superhero muitiplayer rpg where he's the boss of a secret organization after that one. The fantasy rpg becomes real and one of its goddesses summons him in his superhero rpg avatar so he has no magic...
@SunSun It's acting like collecting signatures to change something. I don't think he would have understood that having only that piano would be a problem unless a large number brought it up