>>101663009He did absolutely nothing wrong. In fact, I'd claim he's not even evil for championing the national liberation of his people.
The Butterfly family are fraudulent, incompetent oppressors. They have invaded the land that the monsters resided in, they have ethnically cleansed it from them and pushed them deep into the woods, all while keeping their own citizens in poor living conditions as they comfort themselves in luxury.
Star's liberal solution of merely paying repatriations and letting monsters live in the same poor conditions as the citizens of Mewni, yet keeping the monarchy in-tact to continue oppressing them equally, is an insult. The monarchy should get abolished, once and for all.