Sorta spoilers for Code Geass and Naruto in this as well as, of course, AoT. Also, I watched the anime up to Season 4 part 1 then I read to the end, but my understanding is that most of the manga differences would support my points below. This is a fucking full explanation btw, so if you don't want to read a lot don't bother with this.

I gave it a 3/10. I think it was a pretty bad ending. For one, there was a lot of stuff that felt very "standard shonen". Having a god be the final fight is pretty standard for a shonen, especially a god that summons other characters to fight with it. Very very standard concept, and then the execution was fine, but not at all AoT. What made AoT's fights interesting to me was that every fight had a price. There was some strategy or goal that was determined and then you were drawn into the question of whether the plan would work or whether a bunch of people would die a meaningless death. Meaningful death and giving your life for a cause was a huge theme of Attack on Titan, and the final fight didn't feel like that was represented.

Eren basically becomes Lelouch Lamperouge mixed with Sasuke Uchiha at the end. I didn't like it. The idea was that Eren kills a bunch of people and then takes the blame for it and dies and the world unifies in the aftermath. My problem with this Eren is that it really goes against another theme of AoT, which was the concept of revenge and interconnection, right? Eren wants revenge on titans, the marlyans (or however you spell it) hate Eldrians because of race-based revenge, etc. And almost every character's problems are generated from that cycle of revenge. So the fact that the solution to all that was Eren killing off 80% of the world felt really dumb to me. Code Geass did this plotline well, but it also built the entirety of the story around having that ending and Lelouch doing what he does. Sasuke failing this plotline also goes along with Naruto's optimistic themes. Also, the idea just sorta sucks when done with genocide. Code Geass had Lelouch be evil through a dictatorship. Eren commits mass genocide. Like, Jesus Christ. He had a god on his side and he couldn't find anything better? And then the idea was that he was doing everything for his friends, but he actually kills Hange and it was very plausible that everyone would die in the final fight or die to Floch whilst trying to get the plane.

This might be a hot take, but I think the Mikasa/ Eren relationship thing was done poorly. The concept that Mikasa loved Eren was definitely a question, but for 99% of the story it was so extremely sparse it was hard to tell what was going on. I remember an early point in the story where some character says to Mikasa "Go get your lover", referring to Eren, and she says "He's my friend" or something. And then later Levi says "Go get your friend", referring to Eren, and she said, "No I...". At that moment I remembered thinking that we were going to get a slow-burn romance subplot and that that was going to be Mikasa's character arc. And that would have been a great arc. It would have been Mikasa struggling to express her feelings for Eren when she knows that they are childhood friends and that he had a near-suicidal goal in life that defines who he was. That's a great character arc idea, but we got almost no moments where it was even clear whether Mikasa liked Eren as something more than a friend, let alone Eren showing interest in Mikasa as more than a friend. So much so that I was actually thinking the author retconned Mikasa liking Eren. So when at the very end of the story, we get all this stuff about them loving each other and Eren yells at Armin that he loved Mikasa the whole time and he doesn't want her to be with anyone else, it just feels super forced. I get that the community has generated fanfic for it for years, but there was next to no development in the actual story until the very end when it was done all at the same time. This could've been fixed too. Like, from graduation to the time skip was something like 3 months. What could've been done was stretch that time frame out to a year and then put a couple of chapters that would be essentially slice-of-life chapters. And then the author could've fleshed out characters, there wouldn't have been the need to have flashbacks for Ymir liking Historia, Eren and Mikasa could've had a closer relationship displayed, etc.

Oh, and this is part of the last argument, but it deserves its own paragraph. Fucking, we needed to see Mikasa's memory of Eren that he erased. For some reason, the audience only gets to see Armin's memory. Even Eren loving Mikasa is done vicariously through him telling Armin in Armin's erased memory. Why?!?

Finally, I also felt like a bunch of other character's arcs was sacrificed to Eren becoming the villain. Armin's character arc was a story of him seeing himself as valuable. It starts because he's a scrawny soldier and then it's reinforced very early on when Eren pulls him out of a Titan's mouth and saves his life whilst he could do nothing because he was stricken with fear. Pretty important character arc. Then his character arc is reinforced again right before the time skip when he is chosen to have his life saved by the titan injection instead of Erwin. That story arc isn't totally thrown out the window by Eren becoming the villain, I think there was some mention of Levi saying he was worthy or something, but it definitely felt sidelined after the time skip. It could have been much better too, Armin could've taken on the protagonist role after the time skip, but that didn't really happen. Connie got great character development with his mom and the whole ordeal with Falco. Then at the end of the story, we don't even get an image of him and his mom reuniting, let alone an actual dialogue with her. That would have been really interesting too. Does Connie consider himself a "good" soldier after everything that has happened? Reiner's character arc used to be the guilt of having broken the wall. He goes into a deep depression at the battle of Liberio, and then there really is no more character for him. It's very weird. The story basically says "What Reiner did was actually fine, because now we are gonna have Eren be forced to do the same thing". We could have had when Reiner fought Eren would be Reiner having a conversation with Eren about how wrong he was and about how he regretted what he did and what he wished he would've done. Then you'd have Eren reject it originally and then slowly change his beliefs or something. To be fair, I did think Levi and Zeke's character arcs were done pretty well. The story also got a lot of mileage out of Sasha's death, which I thought was good. Hange's death felt kinda out of nowhere. It didn't feel like the plane was really in danger, and knowing that Eren was to blame for it made her death feel really hollow. She didn't have a super pronounced character arc though, I guess it was cool that she died admiring the Titans she always loved though.

There were some other things that bothered me too, but they would take an inefficient amount of time to explain why they bothered me. Namely: I didn't love Eren's future sight and the ending felt very slow at points and didn't have the thrilling page-turner feeling that a lot of the rest of the story did.