This film's plot and characterisation is too complicated for me to quickly get my head round it, but is this Erik possibly a kind of robot or android who may incorporate screws in his body? Alternatively, I randomly found a quote (link below) saying that a character called Erik can "control all forms of metal by using his mind". If that's the same character, perhaps "Raven" is worried that he will use his powers to move some metal objects somehow to his advantage?
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.