The final battle was fun, Hegemon Edelgard wasn't as fun to fight as Rhea, but she was still a neat boss and like Rhea served as a good climax to the Blue Lions since of the antagonists in the game she's the most thematically fitting for them. I do wonder why she tried to stab Dimitri at the end, she's not shown to be that spiteful in the other routes so it's interesting that here when Dimitri is trying his best to save her that she fundamentally spits in his face like that.
As for the story, I really enjoyed Dimitri's character arc. With most of the other lords, while they endured the same trauma that he does, it's rare that the stories show how much anger and negativity it can instill in a person when you endure that type of loss. The closest I can remember would be Lyn as she hates the bandits and admits that she wants to go off and kill all of them, but it's only touched on in the Wallace support and it's concluded within it. Dimitri is the first that focuses on it in the story and gives depth to it as from the beginning it was pretty clear that there was more to that kind face that he was letting on and as the game goes on it does a pretty good job shedding that face and showing more of that darkness. Once he finally snaps it's easy to see how his character transformed into a wrathful version of himself, and that continues into the timeskip arc where he's making decisions based off of anger then what is better for him and others. His arc where he reverts back is still good, but I do feel there's a couple more holes in it. The first is that I feel that he could've used a chapter between the bridge and his epiphany moment at Gronder Field as you can tell he's starting to snap out of his wrath in the former and he does in the latter, but the in-between doesn't give him a good transition between the two. The second is that they could've done more with the stepmother plot point since it's a major revelation that she had a part in the tragedy, but it doesn't really lead to anything major since she never appears nor is what happened to her explored, so it's an odd loose end since it could've done more for the character (and Edelgard as well, but it's not her arc). Overall, it's still a good character arc and something I'd like to see more of since it plays on the typical tropes that we see in the lords.
As for the rest of the story, I do like that the secondary cast feels more connected. With the Black Eagles and Golden Deers the characters are more like people from separate backgrounds coming together, but with Blue Lions it's more like a group of friends heading off to school and it makes their dynamic interesting to see, particularly in cases like Felix where his brother's death really plays into how he interacts with Dimitri, Sylvain and Ingrid. I also liked how they were connected to the bosses as seeing Ashe's reaction to Lonato's rebellion and Sylvain's reaction to Miklan turning into the Black Beast gave it a bit more of a personal feeling since I'm seeing characters with connections reacting to what's going on in the story. In particular I feel Mercedes had the biggest once since she's related to the Death Knight, and once you get her paralogue you get to see a bit of how her brother's transformation into that villain makes her feel guilt for not coming back for him despite knowing how his father's family was no good for him. It also made the Death Knight a bit more of a character for me as he mostly coasted on cool factor, but after seeing his relationship with Mercedes I started to like him more.
All in all, it's a great route. I'm not quite sure where I'd place it as some of the loose ends like the aforementioned stepmother and TWSITD (they really don't like doing much with them after the timeskip) bug me, but it's still a good arc. As someone said earlier, it's basically a typical FE story with a twist, particularly with the focus on its lord.