Pros:
After the end of the anime, I was wondering how the sequel movie could possibly continue the story

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with the main cast seemingly intact (based on the poster)

and Rebellion managed to deliver exactly that.

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At first it seems like a very different alternate timeline, where Kyoko is part of the same school as Madoka and Sayaka and also knows them before Homura transfers to the school. On top of that, Mami also has Charlotte (the witch that killed her in the anime) as a pet and calls her Bebe. It feels a little too perfect. As you keep watching, there are other inconsistencies that appear, like the Holy Quintet calling the evils Nightmares rather than Wraiths. and the very abstract backgrounds. In the original anime, the abstract and weird backgrounds were reserved for the witch dimensions, so seeing them being partly applied to what is supposedly the real world, raises a lot of red flags. These clues are what foreshadow the fact that the movie takes place within an illusion created by a witch. Except that raises further questions, since witches shouldn't exist either. Finding out that Homura is a witch and is causing the illusion herself is surprising but the progression to get there entirely makes sense. You at first assume it's Bebe since she was a witch in the original anime, but then Sayaka reminds Homura and the viewer, that Homura is the only one who remembers Madoka and witches.

For nearly the first half of the movie,

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Kyubey doesn't talk once, which is so that he falls into the background. The movie is trying to make you try to forget that he's there and implying that he's just chilling this time around and isn't up to anything. This effort is contrasted by the same unnerving close-up shots of his face that the anime had. So it doesn't come as much of a surprise when it's revealed that Kyubey was the true cause behind the illusion by blocking the Law of Cycles with an isolation field. His motive makes perfect sense as well, he simply wanted to see what would happen if a magical girl were to reach their limit while being out of reach from the Law of Cycles.

This is foreshadowed wonderfully by

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the post credits scene in the anime where Homura tells Kyubey about Witches and how the world used to work before the Law of Cycles. All Kyubey wanted to do was test Homura's claims, but it still makes him a wonderful antagonist.

On a less important note, the fight between

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Mami and Homura was really cool to see, since they don't fight in the original anime. It was exhilarating to watch, I genuinely thought one of them was going to die at different points in the fight, especially when Homura shot herself in the head.

The fight isn't just pure aurafarming though as it does have some thematic connections.

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If Homura had just talked to Mami as to why she was attacking Bebe, the whole fight could've been easily avoided. But this plays into Homura's flaws, she still has a distant attitude from the time she spent time looping, feeling like she has to do everything herself.

Having

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dead magical girls like Sayaka and Bebe become Madoka's helpers is a great idea. It allows sequels to keep existing characters around and also opens the opportunity to explore the human versions of witches that were fought during the main series,

which in itself is an idea that could be used for countless spin-offs. The idea isn't entirely unprecedented either since

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Madoka does talk to Sayaka's spirit at the end of the anime. It's also foreshadowed in Rebellion by Sayaka remembering witches alongside Homura and being the one to remind her of the truth.

Neutral:
Rebellion introduces

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the human form of Charlotte, Bebe as a new character which is great as I just mentioned. Except they use her human form in only two scenes and the only characterization we get in those scenes is that she likes cheese. It's to the point that the inclusion of her human form feels pointless. They could've just kept her in Charlotte form and only a couple lines would have to be given to other characters.

If you're going to introduce a whole new character that you include in marketing materials, you need to do something with them. Imagine if we got a scene that

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delved into her past a little, what type of magical girl she was and what her wish was before she became a witch.

The rest of these sections are related to

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Homura

, who is the most important character in Rebellion, but conversely also the one I feel is the most mishandled.

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Homura feels terrible because she's the only one who remembers Madoka, which is entirely valid and understandable. What I don't understand is how her character regresses to how she was before the end of the anime. She's once again trying to save Madoka by herself instead of letting Madoka make her own choices. I get that she wants to have Madoka by her side, but that's a sacrifice she made herself and trying to deny that is be incredibly selfish. I thought that Homura learned her lesson at the end of the anime. She realized that her approach wasn't working and when she finally lets Madoka make her own choice to become a magical girl, she manages to overcome Walpurgisnacht. On top of that, Homura should've remembered that even though Madoka doesn't physically exist anymore, she's still looking over all magical girls, a part of her will always be with Homura. This is even signified by the red ribbons that Madoka gave to Homura. I'm willing to let this slide somewhat because seeing Madoka in the flesh again due to the illusion probably reopened Homura's wound of wanting to save her, possibly even stronger this time around, since she thought she had already lost her for good and becoming a witch might've degraded her critical thinking skills. But her solution to save Madoka the second time around is to control her even more, which feels especially hypocritical, since it's the exact same thing Kyubey was trying to do earlier in the movie. Instead of realizing the error of her ways a second time, she doubles down she stoops further down to Kyubey's level. It feels like she's saying: "It's bad when Kyubey controls Madoka and learns how the Law of Cycles works, but it's fine if I do it."

Cons:
The worst part of it isn't the why though, it's the how.

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How did Homura have the power to become a demon? Everyone had just escaped the illusion they were trapped in and Homura should've had little magical energy left to use due to the advanced state of her curse. Subsequently Madoka arrives in her goddess form to cleanse Homura's soul gem and take her with her.

This is where the movie should've ended imo. What should've happened is that

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Homura finally realizes the error of her ways, has a heartfelt conversation with Madoka and goes along with her to join her as a helper alongside Sayaka and Bebe. What happens instead is that Homura doubles down on her selfish wants and somehow manages to separate Madoka from her goddess form.

The explanation as to why this is possible is piss poor, which is that

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she used the strongest emotion there is, love. Usually I'm all for the power of love, but this isn't it. You're telling me that the love of one person is stronger than a literal goddess that was formed by the karmic entropy gathered across multiple timelines? I will concede that Madoka probably wasn't at full strength due to still having a tangible body, but I still call massive BS. Nowhere was it established prior that Homura had the power to do something like this.

The end result of this baffling choice is an unsatisfying ending that feels unfinished.

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Homura (possibly) absorbs some of Madoka's powers and changes the Law of Cycles so that Madoka is still part of reality. This creates a new reality where Homura is in charge, which is very similar to the illusion at the beginning of the movie. The only difference is that this time Homura caused it on purpose rather than inadvertently. The movie ends on the rest of the Holy Quintet vowing to fight Homura and overthrow her warped reality,

which doesn't feel satisfying in the slightest. It feels like the entire last act of the movie where

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they fight Homura a second time

is missing from the movie. It almost feels like Magica Quintet is needlessly extending the main series rather than letting it end on a good note. It feels pointless as well, since they ended up creating a bunch of spin-off material in the mean time, (that could've been used to explore this concept instead) and waited 8 years to start creating the sequel movie to Rebellion. I feel bad for fans who saw this movie when it came out and have had to have lived 13 years with this ending. I hope to god that Walpurgisnacht Rising wraps up the story on a satisfying note.

Overall:
Madoka Magica the Movie Part III: The Rebellion manages to follow up on the anime's masterpiece of an ending in a way I considered impossible. It has excellent foreshadowing and

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Kyubey

is a great secondary antagonist. However

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Homura's

characterization is botched and the movie completely drops the ball on the ending, which feels unsatisfying and unfinished. If Walpurgisnacht Rising ends up being good, I would recommend watching both movies back to back, to mitigate the ending of this one.