How much of the show is accurate?

Louis de Saint-Just and Maximillien de Robespierre didn't have such different ideas irl, contrarily, they were loyal to each other and they got killed together on the same day by counter-revolutionaries. But in the anime, they are like biggest enemies and that's ridiculous. In the anime, Robespierre always behaves like a moderate revolutionary and Saint-Just always behaves like a radical extremist but irl both of them were members of a French revolutionary society that is radical revolutionary af called the Jacobins or the Montagnards. Laterly, some fractions appeared in the Montagnard society. Some revolutionaries like Danton and Desmoulins found Robespierre so cruel and critisized him, in the other hand some radicals called "the Hébertists" critisized his new-social-religion project called the Cult of Supreme Being as being so "theistic" and offered another new-social-religion project called the Cult of Reason which was way more "state atheist" and "anti-theist". Despite these fractions, Saint-Just and Robespierre always stayed together and have never had an argue.

The black knight stuff I think it’s not real (not sure) while Fersen relationship with Marie Antoinette is real. Till today historians don’t know if it was platonic or romantic, but there are a lot of documents supporting the theory that it was a romantic one. Fersen was also related to the American independence war and to Louis XVI failed escape.