Another Idea is to look at their physical manifestations. Are they back in their own bodies? what condition are those bodies in? are they ghosts/spirits, with the living oblivious to their existence? Can the living see/touch/sense the creatures after them? just some thoughts.
Hi. I think you should make them enthralled by anything, anything happy at all. A nice day, a passing butterfly, a friendly dog, anything. Having been in hell they must have forgotten joy and now have a lot of it and its hard for them (emotionally) to feel it
Isn't there a paradox in your MC? You ask how people from Hell might act, but I wonder if that characterization would apply to your MC. After all, he lacks an important character flaw shared by everyone else from Hell...he is not a sinner, making him significantly different.
But he still would have been through Hell, literally, so he's still gone through unimaginable torment. Otherwise he (TC) would have just asked how would evil people act.
