For the people who don’t get it: To the Greeks (who primarily spoke Greek and Latin,) Germanic and proto European languages (like old English) sounded funny. The Greeks joked that it sounded like “barbar barbar” which is basically the Greek version of “blah blah blah blah”. So the people who spoke those foreign languages got referred to as barbarians.
It was basically used as a pejorative. It was a way for Greeks to discriminate against non-Greeks.
I took it to mean the DM was going to start throwing all the Herculean labors at them, then have the characters wife accidentally poison him, so that he burns himself alive on his own pyre.
It means they speak another language. It's onomatopoeia for how they heard foreign languages bar bar bar, so they became the barbarians, those that speak bar bar.
A long time ago, I saw fan art of this show and was intrigued by the colored visors. I tried to find more information about the show without success. I've been looking for this one for a long time, thank you very much for such a quick response.