great ideas, and i would love a custom! part of what endeared me to the ladies in the reboot was that nobody was a badass right out of the gate. they were regular people (albeit smarter than average) who made mistakes and had to find their footing. so i appreciate your character paying homage to the movie in that way. as far as kevin goes, he comes equipped with plot armor. it's mighter than the sword and the shield!
in all seriousness, i'm considering saying that his possession left him with mediumship or some kind of spidey-sense. nothing that would make him overpowered or even particularly useful in most cases. just a little something to help tie him into the plot better.