Ok for the tomahawk and the key but after I don't understand me toi. ...

Peut-être pourrait-on faire la map ensemble ?? 

I do not how understand to begin the secret, somebody could help me ? ( sorry for my english  )

Shoot in the 4 balls in PaP room and you can find the hell tomahawk and after kill panzer you can pick up a key and i am lost here....   ( sorry for my english too )

Yes I found the tomahawk !!! (sorry for my bad english)