Oh, please. They're not sociopaths at all, because by the standards of their society this is perfectly normal behavior and not "anti-social." Saying that they're just animals that look human takes it to even more absurd extremes. There's very little that we see them do that would shock a Roman, medieval European, or really pretty much anyone else in human history up to the early 1800s. Empress Hoshi gaining massive military superiority and declaring herself to be in charge would fit right in with a huge number of historical leaders.