In the original 1988 film, the summoner, Ed Harley, eventually starts feeling the pain and seeing the actions of the demon as it kills its targets. A modern feature could expand this into a mechanic or narrative device:
To better understand the creature's origins and the atmosphere of the original film, watch this detailed retrospective: Pumpkinhead
: Every injury Pumpkinhead sustains is reflected on the summoner’s body, but in a non-lethal, decaying way. If the demon is shot, the summoner develops a weeping wound that smells of pumpkin patch rot. In the original 1988 film, the summoner, Ed