Mirror Principal Celestia 1.0  
Also Just a quick concept that went how things could have started in the mirror-verse.
 
Sunset finds the book, she experiences the magic herself to some extend and is certain her principal celestia will love it just as much as she does.
 
As she goes into the prinicpals office she uses the magic on her and Celestia is without doubt enjoying the trance she’s put in.
 
Unfortunately once the principal’s out of her trance and reached 1.0 she’s freaking out, not understanding how what just happened to her is possible. She demands Sunset changes her back, but gets told it’s impossible. The principal thinks with the way she looks she’ll be ridiculed and word will spread quickly to the superintendents, she would loose her position.
 
But just before she’s about really scold sunset and give her a what for, Raven enters to deliver some documents totally unfaced. Celestia is asking Raven if she can’t see that she looks different, but gets the usual reply of “New mascara?”. Soon the memories of Celestia altered life begins to take hold of her, appreciating her body and the drive it brings with it.
 
Now that she knows she can get away with it she’ll make this school into her paradise (later city- and possible world domination comes to mind). She makes 4 or 5 staff and student changes until she decides to bring sunset to her sister to change her as well to 1.0, after some first step changes to the school and they got more confident in the magic’s uses, both sisters decide to take it up to the next level as they accept more magic and jump to 2.0 together.