I vaguely recall that at some point in the 1990s, there were ads published in various Marvel comic titles, for a contest with some sort of promise to make the winner into a Marvel superhero -- specifically, the fan would be the temporary embodiment of Captain Universe, as host of the Enigma Force's Uni-Power. I believe the ads featured full mask versions of the costume, like the art shown on the Captain Universe TV tropes page, in male and female versions.
I don't recall for sure if Marvel actually promised to include the fan-based character in some role in an actual canon comic or not, Earth-616 or otherwise.
What became of that? Was a winner formally announced? I see no mention of this on the official Marvel site's character capsule, nor in the Wikipedia page.
Something that I thought that might possibly be connected, is something mentioned on the Wikipedia article in the table for Other Realities, where a couple of enigmatic entries appear:
So I thought perhaps it could be related to the 2000 Universe X, but I see no further evidence for such a connection on the Wikipedia page for Earth X and Universe X.
Or am I remembering wrong, and it wasn't a contest, but perhaps some sort of gimmick where they'd send anyone who mailed a check some marginally personalized comic?