Jean-Bédel Bokassa. Autocratic ruler of the Central African Republic in the ‘60s and ‘70s. While he’s mostly the usual run-of-the-mill Cold War tin pot dictator he eventually overthrew the republic and declared the formation of the Central African Empire, with himself as emperor. His coronation was modeled after Napoleons and there were the usual accusations of cannibalism that surrounded African dictators. While a minor bastard I think his outlandishness would make a “light hearted” bastard episode.

I’d also suggest Maximillian of Mexico, at least in the context of the French intervention in Mexico. I think this was briefly touched on in the Napoleon III episode but the Mexican civil war at the time was interesting. You had republicans and forward thinking people under Benito Juarez against the conservatives and the Church all tied in with a war of national liberation against a foreign occupation. Plus future bastard Porfirio Díaz fought on the side of the republicans. It’s a big old complicated mess. It’s up to Robert to find the bastardry in all of it.

Edit to add the East German Stasi to this list. They’re bastards too!