Happy Nightmare Night everypony. It seems I was able to make it feel a little more festive after all, albeit somewhat lackluster. 

 >>/7979/
> Originally, they were found in that state and if you take into account Nightmare Knights and the previous arc
When counting that as canon, makes Twilight Sparkle and Cadence very interesting. Do/should they have such a state as well, though such as a tangent. 

> Tons of gray arise here but I guess that what prevented them from being evil comes from their well-settled values from Starwsirl (putting his faith on them) and the amount of responsibility that they hold, how committed they are with their duties.
If one takes power being driven by emotion, might a comparison to the lingering temptation of the darkside of the force be made. I remember for awhile FiM trying to make a point of magic being based directly on how a pony feels at that moment (or something like that, been awhile since watching season 6 or season 7). 

 >>/7973/
>  and as NMM was proven to be too weak
I have seen the point made with the Season 5 alternative timelines that one might take that Nightmare Moon's was the best of them and she seemed to have dealt with all other threats and had stability, as opposed to the various others. Not a hard canon context but something that is interesting possible counterpoint to this:
> it doesn´t mean that she can beat her sister
Though that does risk going on a tangent as well.

 >>/7974/
> Luna,no matter how she looked,holds her actual behaviour because of her special context and she,surpassing the duality of being a hero or a villain,is depicted as a grown up character that acknowledges what is right to do. Instead of delivering a NMM look,her armour replaces said infamous appearance (even though the whole squad was roleplaying with said costumes) 
I think, with her embrace of Nightmare Moon as a persona, is a interesting one. It does reflect maturity but when paired with Do Princesses Dream of Magic Sheep I wounder if there is a slight darkness that does exist with this. I like where you went with this though...  though I haven't gotten to reply to my liking, haven't brought up her transformation... but that would risk a tagent