[Pixio]

I am confused by the Combine and turn-in process. On Wiki, it says that any of the 4 NPCs can perform any of the 4 combinations. Is this true? Also, on the 4th Piece of Staff part, after combining, do I HAVE to take it to Polzin Mrid in the Hole for the 4th piece, or can I give it to any of the other NPCs to receive the 4th piece?