Ghost, Hamlet
Take your pick from any of the cinematic interpretations of Shakespeare’s classic tragedy; reliably, the ghostly King Hamlet shows up, tells his son he’s been murdered by his brother, tut-tuts about his widow marrying said brother, demands his son avenge him, and then peaces out… only to show up later to tell his son he’s not doing a good job with the whole vengeance thing. Maybe “incompetent” isn’t quite the right word to describe this behavior, but why couldn’t Pops use his supernatural powers to help his son move the needle a little?
