So I just saw your pony au stuff and this looks so cool! I am curious though since they weren’t shown but have you done any of the other mlp villains? Sombra, pony of shadows, cozy glow, etc?
For sombra we mostly focussed on the origins for the Umbrums being native to equestria, and weakend by pony love or whatever is stored in the crystals. They used to thrive all over but has since been moved more north due to the dragons taking over most of the south, hence the hostility towards the ponies trying to set up shop smack dab in the midst of Umbrum territory. The Umbrum became desprite, and split off into two different groups, one group deciding that they were better off finding somewhere else (thus become the ROM dire wraiths) , and the ones that stay behind and fight for their homeland.
Sombra still takes over the crystal empire, created soley to win the affection of the ponies than squash their hopes and dreams once in power. the ponies that were able to escape Sombra's iron hooves risked the move down south where they'd face the dragons, taking the infant alicorn princess Cadence with them.
After the empire disapears, Starsworl creates the princesses we all know and love and takes on an apprentice, as he has no children to his name, he'd want to make sure the darkest chapter in canterlot history went in the right hoofs.
which, we both know wasn't the best option, but his heart was in the right direction. The knowledge on creating an alicorn fell onto Stygian, who took the information pretty well, a little too well, in fact he took it to the extreme. What he was trying to acomplish was creating an alicorn with only 1 living participant as the catelist, using dead specimens for the extra parts, this however backfired immensely, creating the pony of shadows.
Now for the last one, cozy glow, for one I think her character is a little ridiculous, at least for mlp standards, like if I could list it;
they send her to pony hell without contacting any parent or guardian on the matter
2. She continues to be held in hell as a literal 8 year old girl, like, celestia hello???
3. I don’t care how evil she is, why the fuck does she go to pony hell, THEN gets turned into a statue, WHAT THE (pony) HELL???? She's the crusader's age for crying out loud!
so keeping all this in mind, I’m going to spitball and see what sticks:
1.She gets awakened far into the future along with her compatriots around the gen 5 era, because of the state of the royal gardens (unkept by useless phone holding feather backs) most of the statues are crumbling to pieces, only cozy’s statue stayed intact due to her popularity with the locals. once freed from her prison, she basically starts at square one, learning about the new world being devoid of magic, so she lays low until she can enact her revenge (or at least until someone fixes the magic issue). years pass, Cozy is all grown up and the magic is still busted, she becomes a royal advisor as the chaos of the gen 5 movie events take place. Blah blah blah magic is restored, Cozy begins her master plan. Summoning King sombra once more (because that guy is never dying in my books) she takes him as her prisoner and uses his magic to corrupt the crystal magic alicron doohicky or whatever. (this would be the CozyX scenario btw)
2.(the CozyY scenario) After some consideration, Twilight decides it would be best if Cozy glow be let out of the Statue prison, with a very strict eye, Cozy glow is put in the hooves of Stygian, creating the villains reformed program. Here, Stygian and Starlight try taking former villains by the bootstraps and asking what they really want in life, Cozy glow wishes she was back in pony hell.
3.(the CozyZ scenario) After cozy glows first attempt at world domination they don’t send her to pony hell, and instead enlist her in a program on the spot.
and that's all I got on them! don't wanna make this thing super long so ending it here.