My question is regarding the rules of shapeshifters of all kinds in D&D 4e. I'm designing a plot in which I want to have a Changeling (or something like it) replace a prominent member of society, with the idea that the party will eventually save the man and expose the shapeshifter. My friend pointed out that Changelings do not necessarily need to keep their quarry alive in order to maintain the illusion of being that person.
My question is: In 4e, is there a shapeshifting race that NEEDS to keep someone alive in order to maintain the shapeshift? I know it is easily house ruled, but if something like this is already in the rules and I haven't found it, I would like to know. I try to keep house rules to a minimum in my campaigns.