What makes you think the cloak wouldn't drive him away?
Earnest, geeky, shy male LOTR fans need a point of commonality with a female before they would dare approach her. Seeing you dressed as a hobbit-ranger-Eowyn hybrid lets him know that you're a fan too... sensing a common interest, he will feel less intimidated and might be emboldened enough to say "hi!" or, "nice cloak!" Once the ice is broken, anything might happen....
Have I ever mentioned I used to be an earnest, geeky, shy, fanboy?