@AC97
 
“You and I are of a kind. In a different reality, I could have called you friend.” - Chrysalis

@AC97  
Their arcs do follow a remarkably similar path until the turning point.
 

 
Starlight Glimmer: I thought Sunburst and I were the same, but we turned out different and it TORE OUR FRIENDSHIP APART!
 
Twilight Sparkle: [Speech 100] So try again! Make new friends! And if something that you can’t control happens that changes things, work through it together! That’s what Friendship IS! And it’s not just MY friendships that are important to Equestria, everypony’s are! When your’s ended, it led us HERE but just imagine all the others that are out there waiting for you IF YOU JUST GIVE THEM A CHANCE!!
 
[Starlight Glimmer is now following you.]
 

 
Starlight Glimmer: [Speech 70/100] When Twilight and her friends defeated me I chose to run away and seek revenge, you don’t have to! You can be the leader your subjects deserve.
 
Chrysalis: There is NO revenge you could ever conceive of that will come close to what I will exact upon YOU, STARLIGHT GLIMMER!!!
 
[You are now Hated by Chrysalis’ Legion]

Is the implication here that Starlight killed somepony and turned them into a plant?

The show behind the scene,  
Starlight : Hey Chrysalis, I like you to meet my new friend. So this is Phyllis.

@Background Pony #CF8D  
Something unprintable here. But Wikipedia’s got you covered.

@BlazinSaddles  
That it’s there now makes it less likely to be a DEM.

@BlazinSaddles  
And what does that mean exactly?

If this turns out to be the deus ex machina of the series, I’m going to throw my hands up to the sky and say Hasa Dega Ebowai.

 
^{%…would you believe I couldn’t find a pony version of this reaction image…%}

Only difference is that Chrysalis does it because she’s basically lost her mind at this point.

phyllis meets twilog.

Those two are certainly Not So Different.
 
They’re both quite magically talented by the standards of their species, they’ve both by one way or another, ruled over a group both with fear, and by being more powerful than the rest, they both seem to be pretty smart, they both can have a temper (Starlight definitely proved she’s more than capable of it still) and this.