Information on the CameoEdit
Mephisto is a demon in the Marvel Comics universe, and one of its several Satan-like figures. He specifically fills the role of a manipulatively deal-making devil, is named after the likewise-natured demon Mephistopheles from the classic fable of Faust, and serves mainly as a villain for the Ghost Rider and Doctor Strange.
Mephisto's most (in)famous appearance outside the adventures of those aforementioned two supernatural heroes, however, occurred in the notorious Spider-Man story known as One More Day. Here, Peter Parker selfishly sold away his happily married life with Mary Jane Watson in exchange for the life of his dying Aunt May, despite May's own acceptance of and readiness for her own would-be imminent death. This story was written specifically to "reset" Spider-Man's history by retconning away much of his prior career, and was widely panned and mocked for the absurd and mean-spirited storyline means it used to do so.
...One More Day.