Image imported from derpibooru 
Original Description:
 
>Sometime later… in a POSSIBLE near future…
 
Rarity: mmmm… this is so… liberating….Darling, you should try the thermal vents down there near the abyss… and also try holding that contraption that Sunset Shimmer and Sci-Twi brought to the pier…. Why so serious, darling? Catfish got your tongue?
 
Twilight: Sigh Here we go again… some things never change, regardless of the dimension… Rarity, control yourself, we need to return you to normal…
 
Rarity: I do not want to be normal anymore, darling. I now have a purpose: explore all the fashion possibilities that the mermaid form offers me… the world… I will own the world… of fashion.
 
Twilight: Are you even listening to yourself? Oh, of course you do… I bet you like Monologuing now, don’t ya?
 
Rarity: Yeah, I do… I love to listen to expert advice all the time. And how about you. YOU need an ATTITUDE adjustment, come on, Princess, I want an evil partner.
 
Twilight: Believe me… you will NOT like evil me… I don’t even like myself when I am evil. Been there… Done that… got the shirt… and the scarf.
 
Rarity: Well, talking about fashion… what about if we start by removing that tacky seashell bra. Really…. it is so… cliché, and lets not mention how uncomfortable it is…
 
Twilight: Rarity, I swear to Poseidon…..
 
Part of a series of drawings for :iconannonmyous:, whose SFW versions will be uploaded here some time after being in my Patreon (this one has been up there since November) and soon to add the NSFW stuff up there soon, too.
 
This is a standalone, (as you guessed and as you know) part of the Equestria Girls series of My Little Pony, following my fan-story Equestria Mermaids.
 
:iconannonmyous: wanted to see how the girls would turn out if they became their evil selves from IDW’s “Ponies of Dark Water” comic series
 
I thank you! Thank you! Thank you!