Welp, I'm late.
For how I feel about Corrin in
Birthright and
Conquest, I'll just link my writeups about those Corns.
Although some of my thoughts have changed since them, the rankings of the two Corns remains the same as I ranked them before on my Lord list (CQ!Corrin>Eliwood>Marth>BR!Corrin).
As for Corrin in Revelation, I've said I do not like them, but I feel like I never actually gave a detailed explanation why, so I will today.
I actually think Rev!Corrin had a really strong base, with the idea that no one in the world trusts them outside some servants and Azura, and they need to figure out a way to tell everyone about the true enemy despite the odds.
However, if anyone has seen my complaints with Alm, you would know that I dislike main characters who don't grow over their story, or even worse, main characters who take every opportunity for growth and has it twisted into a reason for them to remain stagnant. Rev!Corrin is pretty much never challenged, and when they are, they somehow always come out right, similar to Alm. However, unlike Alm, where it feels like he's alright right because the writers wanted him to be Jesus, Rev!Corrin feels like they are always right because outside the Anthony arc, they almost has no characterization. In Rev, Corrin has the naivety and kindness the other two Corrin's have, but that's it. They don't have the strong sense of justice and vengeance BR!Corrin has, nor the sense of guilt CQ!Corrin has, which makes the better parts of Rev!Corrin pretty forgettable for me.
The one time I can remember Rev!Corrin actually standing out and acting like a main character going on a physical and mental journey is in the infamous Anthony arc, which was pointless because Corrin barely grew as a character. I don't know if Corrin doubting Mikoto's door shenanigans in a later chapter was suppose to be development from the Anthony ordeal, but if it was, BR!Corrin already had a similar development handled significantly better, which makes Rev!Corrin come off of as a half-assed mis-mash between BR and CQ!Corrin.
Overall, Rev!Corrin feels like a combination of two of my favorite characters that removes the main things I like about those characters. Also, while this is kind of petty, Rev!Corrin making my favorite FE character(s) hated just by sharing the same face also doesn't do them any favors for me.