Finding pics for this was hard, so bare
with me on the explanations for this one.
"After unknowingly purchasing an item that made them switch their bodies in Spells R Us, Nick and his younger sister Christina head back to the store to complain.
Nick was a blond and athletic college player of 20, and Christina was a thin and black haired 11-year-old, but now they’re stuck as each other.
After explaining to the Wizard in the store, he says there’s no way of going back to their original bodies, but he tells them he can ease the changes by having them transform a second time. He offers them a gender-bending potion, so that they can become opposite-sex versions of the bodies they now inhabit. They accept, because Nick is very afraid of growing up again, this time into a woman.
Nick in Christina’s body becomes Christian, a boy version of her sister. He’s still 11 and black haired as she was, but is a little taller, and at least this time he will go into puberty in the right direction.
Christina drinks the potion and transforms Nick’s body into a female version of himself. “Nikki” is as blonde as he was, and as athletic, which in his female version is complemented by being curvy and busty.
Nick can endure living as Christian and Christina is beyond excited about being hot Nikki."