Question and answers
What happens if the Imp is next to a Countess?
The countess only affects herself and any wolf roles next to her, and the Imp only affects non-wolf roles. There is no overlap in the ability of these two roles, as they can't target the same player.
Is the reaper affected by the Imp aura? Or other similar effects.
No effects can alter the Reaper's vision.
If the Blasphemers effect is activated, how would it affect a werewolf that stayed next to an Imp?
The ability of the Imp makes non-wolves appear as wolves. The blasphemer only affects the "actual" wolves. Therefore, those players next to the imp would still appear as wolves.