To be honest, I think every person needs to decide for themself what material does, or does not, harm their walk with God.
Having said that, I first read Dracula when I was around 10 years old. It took a lot of work and multiple trips to the library to understand the context of the setting and some of the more obscure terminology of the time. Since then I've read the novel a number of times, usually with greater insight into the subtext and ideas Stoker was presenting.
At no time have I ever felt that reading Dracula has led me astray in my own personal search for the Truth.