It was a bracelet. He looked around himself and realized that the bedroom belonged to a teenage girl, with a few odd mystical-looking things lying around that most teenage girls wouldn't have. He could only guess that this must be Sydney's room, and it had been kept as it had been since her death.
But the thing didn't look like something a witch would wear. It was bright pink and certainly didn't seem goth. Given the size it couldn't have been worn by someone too young, but it wasn't Sydney's. Maybe a friend had dropped it here once?
He grabbed a hand mirror lying on the desk and looked at his reflection. His face seemed more or less normal, but his arm was beginning to shrink. He had to get out of there, but he was transforming.
On the other hand, if he was turning into a girl, at least there were clothes he could take without walking around naked, once the transformation stopped. He looked around for some clothes as someone pounded on the door, but hadn't yet taken anything when he heard a yell from outside. Someone, apparently Brenda/Sydney, was smart enough to have gone outside to keep him from just leaving through the window. "Give up!" she yelled. "We can't have you leave and give the game away."
"You have to remember!" he yelled in turn. "One of you is my wife! And the other is Sydney's mother! You don't have to let her do this to you--she's dead!"
"We are alive!" yelled Brenda/Sydney back.
He decided he would stay in this room as long as possible. If he could hold them off for even a brief period of time there's a chance Lisa could do something. Meanwhile, he stared nervously into the mirror.
It soon became clear that he was turning into Sydney... sort of. His skin wasn't quite as pale and his hair not as black--Sydney's hair must have been dyed. Did the medallion reproduce dyed hair? Hair isn't alive anyway, so if it could reproduce hair at all, why not? It seemed that what he was turning into was not Sydney the witch, but Sydney from before she became one, when she still wore pink bracelets. That bracelet must have been lying on a shelf for ages as the new Sydney no longer wore it, before it fell on the floor at one point. But what did this mean? Could Sydney possess a body that came from an innocent Sydney? Maybe, but considering how magic works in some stories, he wondered.