Create layered PSD with semi transparent overlay

We are doing some work on the new Deadpool movie. We want to recreate the attached movie posters. There will be two options, one where they replace wolverine inside dead pools blades and one where they can replace dead pool inside wolverines claws.

We need to remove the people from inside the blades and then create a semi transparent layer to go over the top, so that we can photograph a guest and then drop them in but still see some of the detail of the blades/claws if that makes sense.

I have done a very rough version but as you can see its not very good.

Do you think you can help?