Or: Have him play his awesome guy being awesome and even play it up. I don't know what setting this is, if it's fantasy having kill dragons and behead beholders, if it's sci-fi or modern having ride raptors fighting Nixon zombie clones. Keep him separated from the rest of the group and have him do stuff that is way too awesome to be real. Then, in every post, start talking about this blinding light in the horizon that keeps expanding.
Finally, have the player walk in a house where they find his character on a bed, with high fever and being delusional. His parents are standing next to him and ask the players to pull the plug. If they don't, the dad does. The blinding light expands until the power player can't see anything and cease to be. The end.
Professional dickage.