I like Augustus' ability, although I can imagine it being a bit frustrating at times too
Jhonen, however, seems like he'd be pretty overpowered. Clues are so important to the game, and he pretty much gets a free one every turn he's in Arkham, which is probably going to add up to ten or so over the course of a game. Maybe make it so he can only roll a single dice rather than a luck test, or otherwise weaken inspired a bit?