Performing magic breaking the fourth precept(lying)?
I don't personally see any problem with it. Although what you are saying is technically untrue, in the case of stage magic the audience knows that the performer is using sleight of hand and that it's just a trick. It's no more deceptive than telling a joke or a fairy tale. Technically the words aren't true, but the listener knows that. Unless you are trying to convince people that you actually do have powers like some fraudulent faith healers do and stuff, I wouldn't worry about it.