Once you side with Edelgard, everything becomes about her and Rhea going nuts. Which is really annoying since her time as the Flame Emperor and her dealing with TWSD are only touched upon in Hubert's supports and at the end where Edelgard vows to crushed them. You don't even get to fight (outside of text at the end of the route) or interact with them despite them supposedly being Edelgard's allies. They just disappeared after the time skip. That and no one ever finds out that she hired the bandits to kill Dimitri and Claude at the start of the game. And probably the most damning thing for me is her betraying you in the Holy Tomb is never mentioned, not even by her classmates. She used you and your class, ordered you deaths if you try to stop you, and even personally tries to kill you, yet all is forgiven because Rhea goes crazy dragon. Like come on, Edelgard should have been taken to task over that even if you side with her.
That and Edelgard in comparison to Dimitri, whose route is also his personal story that doesn't really focuses on the world, is dull. Edelgard doesn't change. She's less of a bitch compared to her other routes, but she's largely the same and she's never called out for what she did in Part 1. In comparison, Dimitri drastically changes through his story and is constantly called out on his crap to the point that his attitude gets someone he cared for killed. That and probably the bigger character for him is that he tried to make peace with Edelgard despite all the crap he put him through and no one would blame him killing her at that moment.
Third, reasons many of the people side with Edelgard if you chose her are half baked, especially if you compared their dialog to what they say if you side against Edelgard. One that comes to mind is Ferdinand. In his support with Hubert, he actually says that the reason why he wants to be better than Edelgard is because it his duty to guide her and keep her from going too far. He actually dislikes that Hubert kisses Edelgard's ass and not questions anything she does. Yet, he more or less does just that when he sides with Edelgard. Yeah, the public schools was his idea, but it really stands out that Ferdinand never confronts Edelgard about the stuff she did up to that point. Like wasn't ordering their deaths in the Holy Tomb not count as 'going too far'? Also Petra. She sounded the most hurt from Edelgard's betrayal, even asking if she really used them this entire time. Her follow up if you side with the Church is heartbreaking and she gave probably the most compelling reason to fight Edelgard. However, this is all thrown away if she's with Edelgard and is all for 'killing the beast', and never questions Edelgard again about using them.
Finally and my biggest grip with the route, the story bends over backwards to make Edelgard look better and present her as the underdog fighting a powerful god. In all routes, Edelgard is winning the war and even captures Rhea. However, in her personal route, not only is Rhea still at large, but for some reason she stalemated. Why is Byleth joining her make her fall behind and she failed to captured Rhea? Heck, with Byleth at her side, she should have more easily captured. It's really forced and no explanation is given for the change. There is also Rhea being far more nutty. I can buy her going off the rails because Byleth betrayed her, but I find it weird that she didn't go crazy dragon when Edelgard captured her and is sane once you freed her. That and she probably believed you were dead for fives years, so the idea that her mother died again should have set Rhea off and reign holy fire on Edelgard, but it didn't.
All and all, Edelgard's route feels half-baked. Edelgard doesn't change like Dimitri and her story is basically you taking over the world and killing Rhea with no contact with TWSD despite them being your 'allies'. I also don't get why the Death Knight disappears in her route since he came to your aid in Chapter 12 and Edelgard promises to explain everything, and proceed to never tell you anything. And the story have to alternate itself far more than any other routes to gimped Edelgard and empower Rhea to make her more of a foe for Edelgard to take down with Byleth, despite her doing that herself in all routes and even managed to take Rhea alive to boot. The route honestly comes off as a power fantasy where you take down the gods and free the world, with all the grayness from the other side being severally downplayed. Byleth enabling Edelgard and never confronting her over her acts on the Flame Emperor is also a severe oversight and you need to get support with Hubert if you want anything before the end of the game. That and Byleth's reasons for even joining Edelgard are never explored.
This route would have been so much better if they kept Edelgard having the edge like every other route and the story focuses more on trying to keep her in line like Dimitri and exploring more of the flaws in her thinking along with her dealings as the Flame Emperor while also helping her finish her conquest. And while Rhea works as a final boss for obvious reasons, they still should have captured her like they did in all the other routes and explore what was done to her during those five years and the finale should have been them confronting TWSD, who was obviously using Edelgard as a pawn to get their revenge on the gods.
