I haven’t done anything with OCs in a while, but I’m probably gonna do what I usually do and redevelop them as characters for my own fiction.
Lucky Shot was made solely to mark my pony artwork for marketing, except I didn’t actually make much if any pony artwork afterward, so that was a wasted potential.
Elytra and Exuvia are OC no-nos - Chrysalis had five sisters and these were two. Most of the changeling queens besides Chryssy were more neutral towards ponies, except maintaining the whole emotional predation thing. Elytra was a stealth and tactics expert who bunked with Chrysalis and was tired of dealing with the consequences of Chrysalis’s impulsive harebrained schemes. Exuvia kept her own, smaller hive and cared about little other than peacefully being left to her research and anime dakimura.
We had some issues wherein some players were very uncomfortable portraying changelings as sympathetic (not counting intentionally biased CHARACTERS like Twilight, Shining, Cadance) while other players apparently didn’t see any possible objection to ponies willfully welcoming boogiemare succubus monsters who had committed multiple terrorist acts against Equestria into their society.
We were fully expecting Hasbro to do something very stupid with changelings, and Thorax either did or did not disappoint depending on how you want to interpret that phrase.
There’s also the time someone in our open RP tried to switch us into the Cupcakes universe and I solved the problem by making a dark comedy alternate Equestria that frequently badgered normal Equestria and where everybody was a bitter Saturday cartoon villain who abused Gothic & steampunk stereotypes. (Also, not needing to be animated in Flash, they all wore clothes and could not fathom Equestria’s nudity, especially with the Princesses.)
Dusk Gleam, the alternate Twilight, was into magitech / golem stuff instead of just magic, and was so tired of her friends joking about her being a crazy mad scientist that she went “FINE THEN!” and became one with an outrageously fake German accent. Dusk is just as much of a socially inappropriate nerd as Twilight and originally showed up wearing Majora’s Mask, under which she had an Albert Einstein wig and mustache, which she had trouble taking off when her debut antagonist arc wore off. I Noodle Incidented Dusk getting wings sometime after Twilight got them.
Vulgarity, the alternate Rarity, was calmer than Rarity when calm and angrier than Rarity when angry. In addition to her garish outfits (she originally appeared as Rarity’s “butterfly” ensemble from Sonic Rainboom), she swears when angry and secretly runs a “never touch the headmistress” brothel alongside her mildly-more-legitimate-sometimes-adults-only clothing store. Rarity once shrieked about hating green, so I made Vulgarity green with a distaste for Rarity’s specific shade of purple.