When Telliagory dies from a bullet wound he makes a comment about the irony that he lived too long to "die by the sword," since he had lived by one for so long. It seems like another example of his gently dark sense of humor, until you realize what he said to Durand's corpse: "I hope I die like you." Durand died in a swordfight, like an old-school knight. Thus Telliagory's last words are actually a lament for the end of French chivalry.
The opening sequence shows Robin shooting through the royal coat of arms. This seems like it was done simply because it looks cool; but in the final episode, Robin changes his name to Robespierre and becomes the leader of the French Revolution. Only after seeing the entire series do you realize what that scene was actually symbolizing.
The ending sequence features all the major characters, both those who are historical figures and those who are fictional. Robespierre is interestingly absent, despite the fact that he's both a major character and a very important historical figure. It's not until the end you realize the historical Robespierre was in the ending credits all along.
So if Maximilien and Lia are half-siblings because they share the same father and Max's father was Louis XIV, does that mean D'Eon is also the son of Louis XIV and is thus the remaining heir to the throne after Maximilien dies?
Presumably Lia and D'Eon's mother married a nobleman whose surname was Beaumont. She had an affair with Louis XIV and conceived Lia while married to Beaumont. The affair ended and she then had D'Eon.
