WARNING: long and serious post about an old and tired debate over a videogame story
I like Edelgard to a degree but her whole plan makes absolutely no sense. She wants to overthrow the crest-based feudal system but allies with the nobility and a group of genocidal shapeshifters to attack the church and conquer the continent. Her entire power base is exactly the people she needs to eliminate in order to change things, so it makes zero sense how she could accomplish her goals. The game itself can’t even show or explain it, it just states in the epilogue to Crimson Flower that somehow everything worked out how Edelgard wanted. There is no material basis for Edelgard accomplishing those goals, besides the conquest of the continent.
It’s kind of funny because I feel like if Edelgard showed Rhea proof about the slithers they could actually work together quite well. Rhea would want to get rid of them too, and I don’t think she has much of an attachment to a feudal system based on the descendants of nobles who committed genocide against her people and consumed their blood to gain more power. Rhea and the church are certainly influential, but in the way that the pope was in medieval Europe, they have no direct control over anything outside the monastery and the church.
Edelgard’s rhetoric about “them” controlling the continent is just the Fódlan version of antisemitism
This is a simple point but also probably the source of the issue really. The church route was the first one written because they wanted to have a story where your main ‘lord’ betrays you, so Edelgard was designed as the villain. And she is compelling as a villain since she has the right combo of a sympathetic motivation and backstory, willingness to do anything to accomplish her goals, and a poorly thought out implementation that only makes everything worse and leads to countless deaths to achieve a goal that couldn’t possibly happen in the way she was attempting. Later on when they go to write the plot/scenario for Crimson Flower they are already restricted by how they wrote the other routes so you end up with a bit of a mess trying to make it all fit with her being the hero. With more time maybe they could have come up with something better