I suddenly had the scene flash through my head: OP stands in a dimly lit and smoky cantina holding a gun pointed someone sitting at a table and says, "You stole my identity!". Antonio Banderas setting at the table with his feet up, drops his feet to the ground and leaves forward so that his face comes into the light and he says intensely, "It was not theft! I only became the you that you could not be!".
OP says, "That's unfortunate because that me is dead.", and pulls the trigger.

I don't know why it has to be Antonio Banderas, but it does.

Also, as bad as the idea is, it's still 10 times better than the premise behind Face Off.