Okay let's see.
Vision: Of course it's clear to see she is evil, however certain parts of her appearance contradict it. Like how her smile looks more cheerful then evil. It might also be that her eyebrows don't contort to give her that evil style look.
Originality: Your artwork. Nuff said.
Technique: It's beautifully done, and has life flowing through it.
Impact: Hellllllllllllllllllo It's Evil Celene! She has the powers of a God and the evil of Nightmare Moon. That's everyponies worst nightmare! However the one downside I see is that her hair being silver/white really doesn't fit with the new evil her.
Overall I still say it's beautiful. A+++