I'm tempted to use Ultimate Alliance as a cop out for a marvel character, but...
A night elf NPC. I'd be born, grow up, head off to the Exodar and get trained as a Shaman (I'm bound by the rules of the world, not the game if I'm an NPC, that's how I'm thinking it here), I'm immortal so I'd do that for however long and then go to the gnomes and learn engineering then the humans to learn inscription. All in all it'd probably take around two hundred years, but I have all the time in the world. Then I'd set up a shop in my home town and tell stories of my adventures to young night elf NPCs, since none of them are heroes. Probably get bored at a certain point and go exploring for a couple years before coming back and doing the whole "legend of town" thing again. Until I got bored of it again and decided to hunt wildlife with my powers for a bit and come back again to do the legend of town thing again. I like the immortality part, gives me a lot of options, especially when I don't have to worry too much about everyone I love dying, since they're all immortal too.
I've inspired myself to write a story now, good day.