@Proper Prose
So I guess that means Sunset was defied, rejected and abandoned by Celestia, who chooses Twilight instead of her. Which is why Sunset, jealous of Celestia exiles herself to the human world. Also, I think Sunset was so mean at Celestia because she wants to be ruler of Equestria but after Sunset abandoned Celestia, Celestia choses Twilight to be her student. Twilight became a princess, her crown containing the Element of Magic was stolen by the jealous Sunset Shimmer in revenge. And she tried to make it work for evil by turning herself into a raging-demonic queen, so she can brainwash the entire school and rule not just the school in the human world, but also, Equestria by killing and overthrowing Twilight, Celestia, Luna and Cadance, vowing revenge on Celestia and Twilight, and possibly terrorizing all Equestrians with an iron fist. I guess this is something what she should have done many moons ago.

@PonyPon  
Indeed it was… By a tree of all things.
 
May also play into why Shining Armor was made Captain of the Guard. The Element of Magic is also present in his cutie mark. Apparently destiny has an unusual fondness for the Sparkle family.

@Proper Prose  

This whole comic put a new spin on Celestia giving Twilight the of “My most faithful student”. And it’s actually quite said because, looking back, Sunset Shimmer never had a chance at become a wielder of the Element of Magic or an Alicorn Princess (which is presumably what Celestia was training her for). The moment Twilight showed up and Celestia sees her cutie mark that would have the end for Sunset Shimmer.

@Dylanius  
Alucard is more terrifying than that fat ass.

@Background Pony  
@And Brother I Hurt People  
 
Hiii.

Popolestia

Big red lips on Celestia in 3… 2… 1…

Blacklestia is terrifying.

That’s what happens when you steal Princess Celestia’s cake.