A better way to end my story?

My main character is a 15 year old girl who got turned into a Magical Girl by magical creatures and forced to combat monsters. The government also has magical girls under their command, using their powers for their own benefit, as well having spies in schools to look for potential magical girls. Some of the main characters friends and peers are in fact spies and had been manipulating her for a while. She was forced to join, but eventually a separate group was set up so that they won't be under government control.

Then she finds out there are alien spies among the government as well as among the new group. The internal fighting caused by the spies allowed the aliens to invade, which was eventually repelled with heavy losses.

Then they find out that the magical creatures were actually beings from another universe. Their universe was dying and they were trying to siphon energy from the conflicts between the magical girls, the monsters and aliens by making them use their magic, which would be used to keep their universe alive. The war hawks decides to just invade and take the energy directly, which causes a civil war where the main character has to participate in.

Then they realize they were all chess pieces of nigh-omnipotent witches that treated them as entertainment. Eventually, these witches too were defeated and all their combined power is now up for the main character to take.

Understandably, the main character is not really receptive over becoming all-powerful. The ending I have in mind is the main character erasing the witches' actions, make it impossible for nigh-omnipotent beings to do this again, erase everyone's memories including her own, then go back to her normal life before becoming a magical girl. However, it seems irresponsible for my character to just give up on all that power instead of becoming a benevolent god and make sure nothing bad ever happens(the problem of evil), even with the absolute power corrupts and free will stuff to justify it. It also seems like the equivalent of All Just a Dream, which seems like a massive cop-out and anticlimax. How can I improve on this?

I feel that the way to make the ending better is not by changing the ending itself.

The vibes I got from your summary can be summed with "a conscripted person gets traumatised by the fights they're forced to fight what what ends up being no sensible reason, and when given actual power, the kind that lets them be in control, they choose to try making it so that what happened to them cannot happen to anyone ever again, even if the cost for it is their memories". This is different than how you described it, but take a look at it and think, is it not a possible way for a reader to interpret it? And if it is, is it really that bad a choice, that selfish a one, instead of the most noble thing a traumatised person could have done in that scenario?

If you can't see it that way then I am guessing the problem lies with how you look, or how you presented, the character's motivation and all that led them to make such a choice.

In a story of mine, I have a character who is experiencing a Superpower Meltdown decide that the best thing they can do is go into the middle of enemy territory and let their power detonate. It is an incredibly selfish decision, basically spitting in the faces of their family, all the people they'd travelled with, and that's without even starting to talk about the fact that there were people who may have been able to fix it if only the character trusted them, and while they did have a reason to distrust most they did know one whom they absolutely could trust. They later (obvious spoiler: after getting saved) get a lot of flack for it, but not because of what they chose to do, or because they could bring themselves to trust; no, they got flack for what they did because they gave up, because they basically went on their last dance to their own grave instead of stubbornly trying to rise from the ashes as they have always done before, because they were the person who'd inspired the whole party with how much they were trying and now they gave up, because to the party it was the fact that the character gave up that made them selfish and anything else, despite that everything else being the actual selfishness of the character, was treated as the best decision they could have made in their circumstances.

So yeah, I feel that this is a matter of perspective, of how you look at the character and their motivation for making one choice over another.

What about the erasing the events of the story part? Many character deaths, relationships and developments would be gone, which may piss people off. Should I expect my audience to be able to interpret my intentions?

That's a tough question, because I do not actually know any in-depth details of how the world of your story works, and as such am basically making wild shots. Let us hope for the best.

So, let's start by asking this: Of the things that happened because of the character's decision to not become a god-like being, were all of them conscious decisions that she made or were they basically a consequence of erasing the witches? And if it's the former then were the readers shown that the character is close to breaking and upon being given such a choice she would be likely to choose what she chose? Alternatively, if it's the latter, did the character know that the consequences of erasing what the witches did would be such, and if she did then did you show her struggling with it and deciding that this still is the best thing she can do?

The other things that are undone, deaths, feelings, experiences, memories of others, those things make the whole thing heavier, but they will not cause your readers (with a few exceptions, obviously, because that's always the case) to rage if you can justify her decision well enough.

And as for this:

No, the audience has the right to expect from you to be able to show them why the character made the choice that she has. And while I don't mean to sound rude, if the culminating act of your story consists of your protagonist making a super-important choice that will determine the fate of everyone and you can't show your audience why she made the choice she has, how she arrived at it, then something went bloody wrong.

Take another look at my first reply. In it, I'd presumed, even without having enough information, that your story actually does show the character as becoming traumatised by the never-ending fight for survival, that her character is being shaped by it, that the choice she makes is not simply one of the possible choices but rather the culmination of all the went through from the beginning up to the point.

You may be aware of an ancient-as-Babylon Japanese comic and animated series called “Sailor Moon”. The first season of the animated series ends with the main character making a selfish wish that all the girls would return to their normal lives, which leads to them losing memories, to forgetting each other, to ... other things as well. And if it weren't for the fact that the series continued, the whole thing would be left that way. Even then, the only reason they did get their memories restored was because someone else overrode her decision to struggle alone for their sake. Now, this is not the exact same situation that you have, but the point is, in this particular case the wish clearly was a selfish one at least to a degree, and yet it also was the culmination of everything she went through up to that point, and people don't blame her for making that wish because in her situation that was the only choice that made sense for her to make.

You're right, if I somehow still managed to not convey my own message that my entire story is based on, then I am probably the worst writer. As for the decision thing, the main character was pretty much one of the few beings left alive through the whole ordeal. All her friends either got erased, died or betrayed her. In fact, if the witches power didn't gather around her immediately, she would have committed suicide right there, content with killing the orchestrators of the entire thing.

She possess limited omniscience, so it's either staying there forever and try to fix problems across the multiverse, or give it up. She can't just erase the witches' influences, since they did many things across trillions of years, and simply wiping them out may cause their universe to not exist. Problems like her friend's abusive dad aren't caused by the witches, but she isn't going to ignore that part. Dinosaurs going extinct and the Holocaust will have to stay.

The bottom line is that her life since she was born to the moment she finds out that magical girls exist will stay the same. If her changes causes a butterfly effect that will impact her life, then a series of coincidences and outright miracles will happen so that neither will be contradicted.

And that, I'm pretty sure, is the core of it: if.

Just as before, with the info you gave now I am still of the opinion that the choice your protagonist makes is basically the one choice she could have made. Assuming that you managed to convey with many more words what you managed to convey to me with a mere summary, I'm pretty sure that your readers will understand it too.

By this point I have to ask: are you sure that the problem is with the ending proper and not with you not having enough faith in your own ability to do it justice?

The most often criticism I get for my writing is that it lacks subtlety. I wanted an ending that would have less controversy, since I may not be able to convey the reasoning behind my ending without hammering it in.

Well, it's hard for me to provide adequate criticism regarding that alleged issue without actually seeing the text, since a summary is bound to be different from the actual work in that regard and summaries are all that I've seen. That said, I will tentatively point you towards this (found through google, not tasted for poison):

https://scriggler.com/SharePost/Story?cash=5c58306d1b51da4ad8643c57319dfa6f

I will note, however, that while subtlety or its lack (or its overabundance, even) can be of great import to most of the story, it's not exactly the case with the climax of it. Once that particular moment comes, your readers should be able to use the hints you've been giving them throughout the story, subtle or blunt as an anvil, and see that with all that's been going on that one most important choice, the answer your characters came to, makes sense.

Now, certainly, I agree, there may and often enough will be a loss of something, be it quality, enjoyment, or whatever else, if your story is too blunt for what it sells to the readers. But, and there are two "buts": for one, that is not an issue with the ending itself, not in any form, it's an issue of the author's personal writing style and how much they keep to it or go outside of it during their writing, and for two, some kinds of stories mesh very well with blunt as an anvil. Certainly, coming-of-age stories (which your story does at the very least superficially appear to be from what the summary gave me) usually don't fit well with bluntness, but oh well.

Now, if you want my personal advice regarding this issue, rather than just musings I've gone through, I will say this: Finish some kind of version of the book, and lay it off to the side. Then, start writing shorts, drabbles, whatever else you call it (generally 1–3k words), that are of a genre that basically coexists with subtlety; horror (think the original Alone in the Dark) or suspense (the Sherlock Holmes novels in the moments when something is being solved) are both good for that. Then submit those things for critique so that people can point out anything they see an issue with. I've personally found that whatever issues I've had with certain quirks of my own writing style, writing short things that did not exactly align with my personal preferences but that I very much could write helped me get through that.

Thank you, you've been very helpful with all the advice you gave me. I should hone my skills first instead of trying to change my ending. I would probably put a draft of my story in the constructive criticism thread some time in the future.