I think it would be interesting if they added a player character in a Mythos pack that was like a campaign reward, to replace an injured or insane pc. Something like "You may use Henry Armatage for a scenario, if you do so you recover 1 trama." Much like when I am running Call of Cthulhu and a PC dies or goes insane. I allow players to take a NPC that they have befriended that I don't need for story.
I apologize for any grammer or spelling issues I am using my phone.
Edited by Molinext