Obviously we don't know where Matt is headed with Sir Julien (tbh Matt may not entirely know either, that's the beauty of actual play), but something that I'm picking up on already is that in a similar way that C4 is in conversation with C3 about the gods, Sir Julien seems very much in conversation with Essek as a character. And I'm not just saying this cause of the accent.
Like. Essek had all these beliefs, and all this baggage, because he was stifled by his family and stifled by the culture in which his family is enveloped, and he had ambitions. He steals the beacon, he does this horrible, treasonous thing, because he thinks his family and his culture is misguided--the Luxon needs to be studied as a tool, not worshiped. And the only way he can make this happen is by betraying his nation in a literal sense, but also figuratively. He isn't consecuted. He doesn't believe in their state religion. After C2 he's on the run, perhaps permanently ousted from the Krynn Dynasty, despite being a figure of authority within it. Essek is considered a traitor by everyone but those closest to him, which I'll consider the m9 and Verin, maybe? I gotta remember what their relationship is like by c3 lol.
Julien also has all this baggage related to his family and those close to him, and how his beliefs are at odds with theirs. He thinks Thjazi sucks! He's insulted by his rebellion! In the Battle of Maharlian Falls, he thinks he's doing a noble thing--the right thing--because Thjazi is the slimy revolutionary, not him. Yet, the people he cares about most still do not see him as honorable, because their conception of honor is by now so divorced from his. Julien is considered a hero by everyone but his father and Aranessa. He isn't excommunicated from his family, but he's a disappointment his father. He and Aranessa are friends, but he can never be as close to her as he once was (or, for that matter, as Thjazi was).
They're both such cool examples of sacrifice and betrayal and struggling against the weight of a culture's expectations, whether that be a noble house or an entire dynasty, and it's setting up some really cool stuff. By now in CR lore, we understand that Essek was in the wrong, in the sense that he teamed up with some super slimy people, started a war, and screwed over his country. But Essek atones. He realizes what he did was wrong--in fact, he seems to realize it quite early, even before he meets the Mighty Nein, though at that point he's obviously still acting on his initial plans to keep his ass alive and protect his cognitive dissonance. Sir Julien...I can't get a read on if he regrets what he did, honestly. Maybe he will, some day. Maybe he'll have a similar emotional arc to Essek, where he teams up with a bunch of miscreants and realizes the error of his ways, because he was putting all this angst on Thjazi instead of realizing besting Thjazi wouldn't automatically make his dad actually like him, but I'm not sure.
One of the biggest reasons I like Sir Julien, and why I like Wick for that matter, is that in the face of enormous scrutiny, enormous criticism, and the literal censure of the people closest to them, they stick to their guns. In a party of people who seemed to like Thjazi, even if they understand he wasn't a Perfect Dude, it's interesting to have someone make what they see to be a huge mistake but be like no. I'm not fucking sorry. Essek was. I'm interested to see if Matt goes a different direction with Julien.