Since Persona has been suggested and done, what about Naoto Shirogane?
http://www.creativeuncut.com/gallery...hirogane1.html
Naoto finds herself in a lab/evil villan style lair, wandering around, investigating. Suddenly in the dark corridor she sees a figure with a white lab coat, but can't make out who it is. The figure raises a hand, like they are waving at Naoto and suddenly, shadow hands rise from out of the ground and drag Naoto into the darkness. She wakes up in a laboratory, but isn't tied down to anything. The figure in the lab coat steps out of the shadows revealing that it's...
Naoto's Shadow (
http://images2.wikia.nocookie.net/__...pressions3.jpg) (the one in the lab coat ^^; )
Naoto's Shadow gleefully declares she's going to perform another 'body-altering operation'. Naoto rejects this, getting ready to fight her Shadow. Naoto-Shadow smiles and blows some black mist in a surprised Naoto's face. The mist dissolves her clothes. Blushing, she tries to cover herself as she yells at the Naoto-Shadow. The physical changes begin as Naoto's breasts swell and her figure becomes more curvaceous. Naoto holds her head as whatever the Shadow did is also affecting her mind. Her hair grows longer. Naoto-Shadow holds out a very feminin and frilly dress for Naoto. Naoto resists at first, but eventually relents as she becomes her Shadow's loyal slave.
Come to think of it, I could write a whole story for this or even captions for the images, should you or anyone decide to make the images for this.