When I started to wonder. Prue cloned herself so her copies had same powers. It says that Matthew has Power Mimicry and on the page is says it's permanentaly copied.
But as far as I can remember they said copied nothing more. And Melinda was able to erase the copied powers. Could Power Mimicry only Cloning with a added power? Like the two different Astral Projection and Shapeshifting with added power of Voice Manipulation?