Equality? Mayor MARKS?  
That’s it: calling her Mayor Marx. You know, for the proletariat!

“Maredane” is best villain if they write her right.

Looks like Aim toothpaste to me.

Could she be related to the Sparkle family?

@dynamicv  
OAO  
Now that you mention it.

Looks like a falling star to me.

@PonyPon  
Indeed, I think they established that on the first season with Trixie, whose aim was to only show off with her magic, even though she really wasn’t Twilight’s equal in power (or status) until later with an amplifier amulet.
 
Sunset came closer to being a straight up evil counterpart in that she once could have had that same status Twilight had just achieved, but her ambition for that position caused her to lose herself whereas Twilight had earned it.
 
I just hope they can bring something new to the table if they are headed this route with this character.

@PonyPon  
Was gonna add: I mean, Twilight is the kind of person who wouldn’t think of using her nigh-peerless power unless prompted.

@PonyPon  
I only wonder how many times they can still pull this off before running out of traits to twist around.

@Hateot  
Okay.
 
Still kinda seems like a late lesson.

@PonyPon  
There’s not much to go on with either of them story wise.
 
Nightmare Moon was star waving mad, wanted to seize power out of envy and wasn’t seen reigning long enough for it to be called ruling. Other than that everything is a mystery (depending comics canon).
 
Sombra looks to be FIM’s answer to Sauron and other evil overlord types who are not after total annihilation or enslavement for the fun of it. They just are.

@Hateot  
What, was Nightmare Moon and Sombra not enough?

@PonyPon  
This character might come as a warning to Princess Twilight from the get go, right after her princess hood became more meaningful. She’s likely there to show what becomes of people who go for a power trip with all that authority.

@FanOfMostEverything  
I’m sure it’s a coincidence.
 
I hope it isn’t.
 
@Background Pony #A624  
As I speculated before, another this could have been you thing?

Either a stylished greater-than symbol, or just toothpaste next to a star.

The weird thing is that the lower portion is actually close to Blueblood’s compass rose mark.

Interesting.  
The star is extremely reminiscent of the main part of Twilight’s cutie mark. The six pointed star with a white six pointed star rotated 90 degrees underneath. This one only has four points. Wonder if there’s relevance there.

It still reminds me of a > Greater-than sign, but I have no idea what the other mark could be. Maybe it looks a little similar to Twilight’s cutie mark.