I am currently GMing a rather large group of 8 people where about 6 show up regularly, every two weeks. These sessions can be rather straining for me and I am therefore looking for ways to make GMing easier for myself.
One problem that I have found is that one of my players (who I have known for several years and has been part of another campaign for over a year now) needs way more attention than the others and I therefore have to put a lot of effort into balancing face time between my players.
He is also often working against the group and tries to bend the world and the other players to his will (which goes strictly against what we discussed as a group in the same page tool).
Nevertheless I do not want to boot him or something — I would rather make him play a Harlequin (“a player who plays only NPCs”) as I'm sure that he will have a great deal of fun and it would even help me as I have often difficulties playing menacing/evil NPCs!
The issue here is: I told him about my idea, but he said he is already too emotionally attached to his character (although we only played 1 session for about 3 hours so far...) but generally likes the idea. He also personally stated that he really likes the feeling of character progression, not power progression and that he is afraid that as a Harlequin he won't have the same feeling of character growth than the other players.
How can I give a player who is playing only NPCs the same feeling of character growth as the other players with PCs?