I was really kind of a nerd growing up, she tells EW.
I think youll be surprised at her capacity for evil as the season develops, says the actress.
I dont want to give it away, she says.

Credit: Bob Mahoney/The CW
Shes an integral part of the story and Sybils backstory.
Shes motivated sadly, by these tragic circumstances, she says.
Apparently, Sybil has abandonment issues after facing a long-term exile.

When people are motivated by that, Kelley warns, they are capable of some pretty dark things.
Kelley says its what triggers her about Damons love for Elena and everyones love for Bonnie.
She cant fathom that love because shes never had it.
But dont mistake Sybils affection for Damon for something deeper.
Damon can serve her, Kelley says.
Indeed, the siren is not interested in a romantic relationship.
Instead, Sybil prefers to be worshipped, Kelley says.
The Vampire Diariesairs Friday at 8 p.m.
ET on The CW.