Review for Moon's Shadow

>She was no stranger to the midnight visit. Rainbow Dash had been propositioned by many stallions (and a few mares) over the years, and she had rejected all of them.
You do something funny here that I'm not sure a lot of readers will notice, but I have a feeling they'll appreciate the fix whether they notice or not. You say "she" meaning Rainbow Dash, then you actually say "Rainbow Dash", and then—as if you need to—you follow it up with another "she".
This may just be me nitpicking but what if you swapped those first two, and got rid of the last? ex.
<Rainbow Dash was no stranger to the midnight visit. She had been propositioned by many stallions (and a few mares) over the years, and had rejected all of them.>
See how that runs just a bit more smoothly? It's less redundant to say the least, and I think your readers will subconciously appreciate it.

>And so the rumors of her being a lesbian began.
I'm going to reiterate this point. I think you make this jump too quickly. I did a double take and actually had to think about this for a moment to set it right in my head. You shouldn't be confusing your readers like that. You stated that she turned down every stallion that showed up, but then you led them down a rabbit trail by mentioning sex. You've got to bring them back to the rejection bit before they can make the jump "If she doesn't like stallions, then she must like mares" I know it seems unnecessary but if *I* got confused by it, there's at least one other person out there that will also get confused by it. Your choice, but I've made my point.

>Because of the extra pay, she was one of the few pegasi in Ponyville that could afford a pegasus lamp, an oil lamp that worked at high altitudes and could be set to rest on clouds.
That comma ought to be an em dash
<Because of the extra pay, she was one of the few pegasi in Ponyville that could afford a pegasus lamp—an oil lamp that worked at high altitudes and could be set to rest on clouds.>

>She poured in the colza oil, mentally reminding herself that she needed to get more of the stuff tomorrow.
Unless there's a reason to use the phrase "the stuff" such as adding in an *important* adjective, you should try to streamline your sentence a bit more.
<She poured in the colza oil, mentally reminding herself that she needed to get more of it tomorrow.>
The thought is still there, but the reader isn't bogged down with the bulky wording. Also, tomorrow sounds like a present tense word. Just a personal preference but I would use something like "in the morning".

>The lantern sprang to life as light flowed to every corner of the room.
I mentioned this one already. I see that you've fixed half of it but it still portrays the order of events a little funky. Unless you have a reason for this I recommend changing it.

>She may be the only member of the weather patrol that could afford one of these lamps, but that didn’t make colza oil cheap, nor did that make such light easy for her eyes to handle so long into first sleep.
This sentence feels very out of place, adds nothing to the situation, and is also awkwardly phrased and wordy. Personally I would take it out entirely, but you should at least streamline it a bit.

>I'm sure you know about my Luna's history?”
Uh, come again? *her* Luna? Is there a specific reason for this or did you miss it during editing?

>“If there were any other way, I wouldn't be asking this.” Celestia replied.
As a reader (not a reviewer) I'm just going to go ahead and call bullshit right here. If Luna's such a selfish little bitch that she has to go all pissy and turn the world into darkness just because she can't have the mare of her dreams (questionable choice picking rainbow dash, btw) then she's too much of a filly to have the title of a princess. Grow the fuck up, Luna. You're a ruler. Act like one. *ragequits on story because made best princess look bad*
At least, that's what I would say if I were just a reader. Honestly, this makes little sense, and I think the reader in me has a bit of a point. You already pointed out that the stallions who acted this way were more like colts. It would be a shame to put a highly revered princess in the same light, unless of course that was your intent, in which case, carry on, but make it good.

>Should she become Nightmare Moon again, all that anger will be directed at you. I cannot act against her until she commits a criminal act, and I believe the first criminal act would be against you.”
I'm pretty sure she can take that as a threat. Not by Celestia of course, but that is a direct threat against Rainbow Dash's life. Geez, Luna, when did you become so like a newborn foal?



Okay, that's it for the line by line editing, now on to the actual review for the story.
So, what we've got here basically amounts to a disgruntled Rainbow Dash (for good reason) being woken up in the middle of the night to be told that a whiny princess wants her and if she can't have her, bad things are gonna start happening.

I liked a lot of the worldbuilding in here. There are some nice descriptions that really give a good image for the reader. Rainbow Dash is well written also. If I were folllowed around by girls the way RD is followed by stallions, unlike most guys my age I'd probably be pretty overwhelmed and frustrated. Nice job.

A few key points I didn't like were the way you kept interrupting the narration to insert random thoughts which, while they were somewhat helpful, didn't feel worth the break in immersion for the extra tidbit of information. I would recommend learning how to put all of your needed information into streamlined paragraphs that blend into the story.

Then there's the uncharacteristic way you portray Celestia and Luna. If you're using this as your story, I suppose it's alright, but you're going to have to work at it to make it work. If you can, though, it'll probably be pretty awesome on the other side, just keep in mind that it's a tall order, so you'll have to put your heart and soul into it.
Rabbit trail aside, Celestia and Luna are very out of character here. Luna—as I stated—is pretty much throwing a temper tantrum worthy of a six year old girl, and over something so petty as being turned down by a school girl crush.
Celestia on the other hand—or hoof, if you prefer—seems to be afraid of her sister, as though she can't handle the shitstorm that's headed her way. She behaves much like Cogsworth from Beauty and the Beast, "The master is very angry, I would recommend you just do as he wishes."
Both of these issues are not inherently bad if you can make them work for the story, but just be ready for the shitstorm when the readers realize their favorite princess is behaving like a schoolfilly. They aren't going to like it.

With all that in mind, good luck, and I hope you achieve what you set out to do.