depends on what happens next but this really feels like a Damo Tamaki moment from part 8I wouldn't go as a far as saying this has "final arc incoming" vibes. Nothing's clear atm. There's not any indication that the final "villain" of this part is even this Howler guy. We don't know anything at all. Only that these 3 new characters that were introduced have been killed.
it COULD end hear very neatly but we will have to wait and see what Howler does
he didn't even seem to know Key West was a stand user so I can definitely believe someone is pulling strings behind him. That person is going to have to be revealed.