Story search Witches, transformation, telekenetic powers, Las Vegas..

So there is this old story that I believe was never finished that I am out searching for. What I remember is this guy who secretly has telekinetic powers transformed accidently by this pretty young woman. He is Physically flawless and a few times held captive because the family (witches) does not know what to do with her. I know she escapes, to Vegas, I know she has the ability to float high in the air but if she looses concentration falls.
As much as my feeble mind can remember. Gary