Exactly. Mine is kinda like that but they come together in one adventure. Plus the original author (Penstroke Pony) didn't specify his post Nightmare Nyx as an adult. In the end of the story (Judgement chapter) Luna took away all memory of hers from Nightmare Moon leaving Nyx in a pure form yet as a slightly different character. It kinda gives you more creative freedom in how to envision this Nyx as an adult..
I'm glad you like it. I'm already messing around with 4 alternate reality Nyxes 3 of them with freakish mutated power abilities.
Nyx Petite Pie can bend reality when she turns into Abyss and out of control the result is something akin to Silent Hill. In fact if she loses control emotionally while at her Abyss form the power takes control over her, consumes her as the vessel and turns everything into hell. Discord got nothing on her. Her nightmarish power manifested itself when she witnessed her stepfather who tried to protect her get murdered in front of her She represents dark magic and the Earth Ponies (Being born out of an earth pony she has an affinity to them). The unique thing about Nyx Petite is that she is also Luna reborn. Luna didn't survive the cleansing of Harmony (after being completely consumed by the nightmare) after the second Nightmare Moon event and nothing was left but a bunch of shattered armor. Being a member of the Special Forces wing of the Canterlot Army (the Canterlot Special Reconnaissance Guards or C.S.R.G) she's very proficient in explosives, demolition, SNIPING and also pastries.
Nyx Sparkle. Physically the largest and strongest of the Nyxes (even bigger than Celestia) she has hooves down the most energy. Where the heck it comes from nobody knows. When Celestia awakened Nyx Sparkle (at age 15) ability to turn into Zeta Flare it almost killed both of them. (Zeta is a blue super hot star and Nyx was given that name because her coat turns into that color). Fortunately due to Celestia's foresight she brought Nyx in the middle of the crystal desert. When Celestia helped unlock the power of Nyx and witnessed what she was dealing with it was too late to abort. Nyx shot her energy towards a mountain side and with Celestia's quick action she teleported herself and Nyx from that area a fraction of a second before Nyx energy beam detonated a mountain with the force of a 25 MT H-Bomb. Just like Petite, Sparkle's hidden powers are linked with her emotional state. When pushed to the edge too much it awakens. And just like Petite, Sparkle's power are incredibly unstable. Nyx sparkle can only maintain her Zeta Flare form for a limited amount of time depending on how much alicorn magic she has to contain that energy within her body. If her alicorn magic reaches critical low levels her life energy (that which grants her immortality) begins to drain and that's where her body starts to break down. Once her body dies she goes super nova taking all of Equestria with her. Nyx Sparkle represents neutral magic and Pegasi ponies. She is a member of the Canterlot Special Air Service (C.S.A.S special forces wing of the Canterlot Airforce) She's a proficient flyer, fighter (including weapons or just hoof to hoof) and thanks to her mother Twilight Sparkle and excellent magician.
Dawn. cosmicunicorn.deviantart.com/a… She was rescued from a grim fate by Nyx Contacts years ago after Nightmare Moon gave birth to her. The only alternate Nyx that isn't named Nyx. Representing light magic and Unicorn ponies. Of the 3 Nyxes theoretically she is the only one not in danger to lose control or being absorbed by her powers. The problem is that she has zero experience as an alicorn being adopted by the apple family at a young age. Her mother Nightmare Moon disappeared (I still need to decide what her fate is though I think she may have faced off against Nemesis to protect her daughter). Her power is healing, restoration and even her blood has healing properties. Problem is that she's a hemophobe. (irrational fear of blood). Dawn has the personality of fluttershy and despite her being physically strong from doing farm work all day she's still not fit for frontline service as Nyx Sparkle bluntly put it and "wouldn't last 3 seconds against Nemesis". But at her full power potential if she is matured enough (let's say Celestia's age) she has the ability to terraform planets. Nyx Sparkle volunteered to train her. (Celestia in Dawn's reality is pretty much a bitch and wanted to get rid of Dawn if it wasn't for Nyx Contacts intervention)
Nyx Contacts is the one who brings them together to fight Nemesis. I'd like to give your Nyx the pseudonym Sage. (though in your entry zero comic her staff called her November One)
Sorry but her vague likeness to Bayonetta is unintentional. As the oldest of all the alternate Nyxes I wanted to give her the most mature image.