On ice a la Bucky Barnes when he was revealed to be the Winter Soldier? Could work.
And combining Mephisto and Judas Traveller, linking the two most hated sagas/arcs in the Spider-Man mythos? That could work as well. I also like the theory of Mephisto somehow being behind Norman Osborn's resurrection, as a tool to harry and hound and push Peter to his breaking point so he'd be easy pickings for Mephisto's malevolent machinations.