As for the whole Nightmare Knights arc point (and these couple of posts, more like a comment, seem like a comic spotlight) that I have brought up on the previous post,it seems that the Pony of Shadows was looking for different royal sisters so they would fall under his command.
Both NMM and Daybreaker that we see on the NK comics >>2212
(the Daybreaker that was following orders of Eris) are parallel ones. Daybreaker, while she gets some sympathy from the "canon" Luna by depicting herself as NMM (with the help of Stygian's magic >>3654
),she teams up with Luna and they (and the squad) both beat (and Daybreaker kills) Eris. However,this is because the alternate Daybreaker temporarily cares about Luna because the princess of the night was able to look like NMM, she delivered a glimpse that Daybreaker managed to care for a while and make said Daybreaker less of a villain, but she ending up running the casino anyway, asserting that she wouldn't be so nice towards Luna and company. >>3662
The context behind this Daybreaker and a non-existent Nightmare Moon was that the Pony of Shadows wanted to corrupt them and create powerful weapons of destruction. One day,Nightmare Moon decided to rebel against the Pony of Shadows (she rose up against him) and as NMM was proven to be too weak,she didn't make the cut but she displayed better ethics in comparison with her tutor: she defied him and therefore, she was punished for rebellion and personal attack).
Daybreaker, however,has always been really powerful and from that selection,she was the lucky one that would make the cut and become the Pony of Shadows´puppet and then,Eris´ (after tricking the Pony of Shadows). Eris was interested in chaos and have a more lucrative mindset of her world whereas the Pony of Shadows wanted to become powerful by raising ponified weaponry for his destructive plans
Thus,this mirrored/alternate Daybreaker does fall in a gray area as well,mostly because she is running the business as she has always been doing in the past,but she wouldn't show any mercy if she had any newcomers around (neutral without molesting anyone else, but you are asking for trouble if you decide to voluntarily want to step into that place). A villain after all but a more organized and contained in her area than Eris (and way less ambitious in comparison with the Pony of Shadows, but still very harsh ).