Ironic that the princesses are on a higher tier but apparently they(usually most of the time minus Twilight) gets taken out by the villains in some way.

Fan Facts: Chrysalis and Starlight are arch nemesis in canon.
 
Also Cozy and Starlight aren’t villains at the same time in any events, by the time Cozy declare to became a full villain, Starlight is already reformed. Still, both Starlight and Cozy are super dangerous to the point of becoming major villains each of their own seasons when they are up to no good anyway. Trixie’s dangerous level is no match for Starlight, the fact that Trixie was only a mini-villain.
 
Also Starlight is the commie themed villain, most realistic concept of a villain.

And now we got Popo

And below all that, the Spike tier.

Behold the burger tier!

Behold, the only 100% fact tier list.