Hello all, I'm new to this group, and I have a question that I felt would be best answered by members of this group. What kind of situation do you think would lead Luna to believe she has no choice than to change into Nightmare Moon again in order to protect Equestria? What situation would be so grim, so dire that she felt she had no other recourse but to tap into that power and unleash that side of herself again? I'm curious to hear everypony's thoughts on this, and look forward to discussing it with you all.

4628138
Maybe an international war where the very survival of ponykind is at stake?

Or if Nightmare Moon existed as a separate pony, Luna could just send her in instead. *cough*

Discord in stone
at least ONE Element of Harmony is dead or incapacitated
Luna is the only alicorn left standing

Nightmare Moon emerges and destroys the enemy to the point where 'overkill' is an understatement

My cannon thought is that she can't actually do it again. I've always figured more Jekyl & Hyde and less Hulk.
While I understand the basic premise was to give the show some easy to digest history and an action-packed starting point, I immediately thought Luna was neat as soon as she was redeemed/cured/zapped. Now there was a character with some great future story potential!

Non cannon, I've been trying to write something (and I think it's been done, or very nearly done) where it was actually an sentient infection of some sort, kind of like Venom. I also enjoy the stories where they are different characters.

I'm horribly biased though. I have a "Luna is best princess" shirt and I stay up until dawn every day so...... yeah. Moonbutt FTW.

I'd go along with, "She would be unable to do that."
Luna was purified by the Elements of Harmony. Whatever Nightmare Moon might have been, she's dead and gone. There's no canonical reason to think Nightmare Moon was more powerful than Luna in any case. More motivated, perhaps...

4628138
I actually wrote a story with that premise. Griffons get solar magic through alchemy and she decides to keep her ponies safe. Against her sister's wishes, of course.

4628187
I'm glad to see I'm not the only one to have a Venom-like headcanon for the Nightmare.

4628138 i started a story about luna using nightmare moon as a well of power though i didn't publish it and that's not the focus. Essentially i think tyrantlestia would force her to accept nightmare moon though in that situation she would have to be vulnerable as well like avatar-massive power with massive risk- otherwise it's just overpowered like goku in dragon ball

4628138
Makes sense, I've seen a few fics where Luna turned back to Nightmare Moon in order to protect Equestria.

4628213 Not necessarily. She did return and possessed Rarity in the comics only to be beaten again. We all thought she and Sombra were gone but obviously the comics hint otherwise. Especially Sombra being an Umbra and most likely able to regenerate if that ending is any indication. Most likely the Nightmare or whatever she is, is still alive and weak biding her time like Sombra is.

I regard the comics and the EQ Girls to be non-canon, but hey... It's just a show, so go with whatever you like.

Things really have to go to hell before you say, "One more villain running around couldn't hurt anything."

Either Celestia et al. have a secret plan to backstab Nightmare once she's done doing their dirty work or Equestria is so screwed otherwise that giving it over to an crazed, omnicidal maniac is somehow the lesser of two evils.

4630034 Well, who says she'd have to be an omnicidal maniac this time around? Perhaps Luna maintains some element of control this time around and uses it to overcome something that she couldn't in her normal form? Perhaps she could be like Eren Yeager from Attack on Titan and becoming Nightmare Moon would be her equivalent of Eren transforming into his titan form. True, he was little more than a mindless juggernaut attacking anything living that got in his way at first, but he quickly got the hang of it and was able to become the greatest weapon in the protagonists' arsenal against an otherwise invincible enemy.

4628138 Late answer is Late, but there was actually a story I read a few years back where Luna actually used her NMM form as a combat form.

It's called "Not My Destiny". And it was published way back in 2011. Give it a shot and see what you think.

4628138
Really late answer is extremly late:
a) I don't think she fully can transform back by herself, since she needed fake teeth in Lunar Eclipsed to get the Nightmare Moon look right.
b) I would say what would get her to the point of trying to get NMM back/transform again, could be in the Sombraverse from Cutie Re-Mark. She was eager to fight Sombra to begin with when he returned in the show, and facing the prospect of Equestrias demise, something neither Luna nor Nightmare Moon want, her line of thinking could be something like "Rather have Equestria cursed with eternal night, but everypony is mostly free and safe and alive, than dooming it to utter destruction and absolute darkness" (after all, the Moon reflects sunlight unto Equestria, so under Nightmare Moon, there would still be some light, under King Sombra there would be none)

6701996
Iirc Faust(even though she no longer works on the show) answered years ago that Luna can become NMM again if she were to be consumed by negative emotions like jealousy again.
Pretty much if something caused her to snap or be overfilled with dark emotions, NMM would reawaken/return.

Another way of NMM coming back is if something restored/reawakened the dark powers within Luna along with the negative emotions that she was apparently purged from by the elements. Though this time she has to struggle and keep the darkness under control and resolve those dark emotions.
Would have been interesting to see.