I really hatedhis role as the villain. Especially after he learned of spyrites and he was still "durr gotta destroy everything cuz spyrix". Muzet was just worst. Her random insanity seemingly came out of nowhere. Then... all is forgiven after defeating them. The whole thing felt so unresolved to me.
I thought his stubbornness fit his character very well. He was a guy who pretty much united a country through pure willpower and by himself for the most part, so I can understand if he was less than willing to cooperate with something that wasn't guaranteed in the long run. Muzét was a pretty awful villain though, I agree. Came out of nowhere, went insane out of nowhere, and turned good out of nowhere. At least Gaius makes up for her.