Back in 2019 had this idea for an au where those chosen by elements are equines of a variety of Morals. With Ponyville being different to say the least.

Twilight Sparkle: would be a teacher at Ponyville.
The Sirens: Who need to feed off negativity in order to live would strike up deal with Ponyville to feed off the towns negativity as a payment for protecting the the town..that or helping out in general.
Radiant Hope: would be trying to figure out ways to bring Sombra and the Crystal empire back. Living in Ponyville to hide from the Princesses, cause here she still be working along side the Umbrum.

AppleBloom or MoonDancer can't remember which.: Here would be one of twilights students.

Rough Diamond :The thief would be hiding from the cops after her latest hiest.

All of them connected by two things their Friendship(Of Course!) and the fact they don't won't the equestria ruined completely. Not out of moral obligation but personal reasons except for the members who do have morals

7410283
Yeah. I could see this. Definitely has potential.

And, yeah, I could see the Sirens' pony forms resembling a unicorn (Adagio), Pegasus (Aria [because there NEEDS TO BE AT LEAST ONE Pegasus in the group]) and Earth Pony (Sonata)

And, Speaking of fair representation, I would probably go with Apple Bloom instead of Moondancer, primarily because1. there are already enough unicorns in the group, 2. The opportunity to build upon Apple Bloom's canon skills with tools and potions a bit more AND 3. so that we can still have at least one of the other canon Mane Six as a secondary cast member (in addition to being Twilight's student, Apple Bloom is also Applejack's little sister).

And, yeah, I could easily see Twilight and Apple Bloom being the Token Good Teammates of this crowd.

7410337
Huh I was just going to leave the Dazzlings in their siren forms. and Yeah I was planning to have AppleBloom and Twilight be on the lighter side of the Moral scale.
I also had idea of the group having a Stygian someone who brings the elements together but, not being an element themselves.
I was also planning something with the Princess and her "faithful student"

7410384
Actually, I meant the Sirens using "pony forms" for disguises for undercover work (them disguising themselves as ponies for occasions when they need to blend in). Sorry I wasn't clearer on that.

And, indeed, I see your point on somebody bringing the Elements together (though, hopefully, getting A LOT MORE respect and appreciation than the actual Stygian). Perhaps Moondancer could fill THAT role. Or possibly Zecora. Or Spike. Definitely one of the three.

And, indeed, that DOES make sense.

7410491
Okay figured out roles for each siren.
Dazzlings: three sirens who feed off negativity. They have struck up a deal with Ponyville for the Towns protections. Each siren. On occasions they disguise themselves as average ponies. Usually when the princesses are around or her associates

Adagio: The ringleader of the group. Also the one who made the devils deal with the Ponyville founder. The who negotiates with the town mayor.

Aria: The second in command, the one who handles stuff like protecting the town from the EverFree, helping around.

Sonata: in charge of lightening the mood after feeding is done.

Also thinking about it I was going to make the Stygian of the group the princess's student. So it was either going to be Moondancer, Sunset. I wasnt really sure about the students morality which is why I was debating on who to choose.

7412177
Yeah. All of that quite definitely works.

And, on another note, I could see Adagio developing a rather heated, particularly personal rivalry with Chrysalis (since Chrysalis is basically a crueler, less pragmatic version of her in many ways [other than Chrysalis being a Changeling and Adagio being a Siren]).