We just did this show and had the transformation happen full on to the audience, with the actor looking like he was being pulled in different directions by magic. We have a beast mask and wig created for us by a Hollywood Special Effects and prosthetics master. The coolest thing was that the mask moved with the actor's face (as much as possible under that much prosthetics) but came off fast and easily while the actor's back was turned. The adhesive was similar to the strip of sticky gel that holds a credit card to paper when you receive a new card in the mail. Completely gentle on the actor...and extremely fast change. I really like the above idea of the rose petal transformation though! Good luck. Depending on when your show is, the beast mask we had created for us might be available for renting should you wish to do something similar to what we did.