There are three distinct versions of the legend of Marvin McMagicspell. In all three versions, he starts out as a lonely teenager. Around the year 2000, when he was either a freshman or a sophomore in high school, he inherited a book of magic spells that had been passed down from one generation to another in his family for over a thousand years. In the first version he becomes practically godlike in his magical abilities, and thus ascends from earth to wherever to live with the other gods and is never seen or heard from again. In the second version, his misuse of magic causes things to spiral out of control and destroy the entire world. Fortunately, a second, alternate world is created before that happens, and that's the one we live in now. The third version is similar to the first, only instead of the god thing, he simply becomes so powerful that there's nothing he is unable to do, leading him to grow so incredibly bored that he kills himself.
There is also a fourth version, in which none of these things have happened and he's still out there, living among the normal population without anyone knowing the secret of his magic powers. There's also a distinct possibility that none of these versions are true and the whole thing was just made up.