"Vampire Diaries" fans, you may think you know Katherine Pierce, but she's going to blow your mind in the series' September 9 premiere. Zap2it sat down with the lovely Nina Dobrev, who plays both Katherine and Elena Gilbert, to find out what's next for everyone's favorite vampire vixen."Last season I got to do it very little," Dobrev says of playing Katherine. "I was mostly playing Elena, and we teased Katherine a little bit, but this year there's going to be a lot more Katherine. She's back, and she's wreaking havoc, and she's up to no good." Dobrev draws inspiration from Ian Somerhalder's character when she plays Katherine, since Katherine taught Damon everything he knows. "It's going to be fun to kind of step into Damon's shoes a little bit, and kind of play with them and mess with everyone's minds."As you'll see this season, Katherine and Elena may have the same face, but they have very different looks. "Between the wardrobe stylists and the creators, we all kind of collaborate," Nina says, "but I'm very outspoken about the way I want Elena and Katherine to look and the fact that I want them to look differently.""One of the main things is that Elena's a flared jeans girl, and Katherine is a skinny jeans and heels girl," Nina says.Katherine has been through a lot since we saw her last in 1864. "She's meaner," co-creator Kevin Williamson told us. "She's different in the sense that she doesn't have to wear corsets anymore, and... well, I'm scared to say, because it'll tease where she's been."We can hardly wait!Check back with Zap2it soon for more from Kevin Williamson and the rest of "The Vampire Diaries" gang. In the meantime, Nina talks Comic-Con and Katherine in the video below.Follow Zap2it and @cadlymack on Twitter and Zap2it on Facebook for the latest TV, movie and celebrity news.