Right... but /in/ the "Heroes Reborn" universe,
the characters had rewritten origins. Later they
discovered the curious fact that their universe
was only a year old.
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https://en.wikipedia.org/wiki/Heroes_Reborn_%28comics%29>
Iron Man came back with a particular problem - before
Heroes Reborn started, he had been turned evil, then
died, and The Avengers recruited an alternate universe's
young "Iron Boy" instead. But the Heroes Reborn
Iron Man was made from both of them. Essentially
his problem was ours, the confusion.
"Ultinate Marvel" was another re-invent of the world
from scratch, published alongside the original Earth-616
(I think Alan Moore assigned it "The Number of the Beast"
in Captain Britain stories because... he is Alan Moore.)
It had its own Spider-Man, and its Avengers were called
The Ultimates. Eventually these became parallel universes,
then deleted, and 616 was recreated but is now called
"Earth Prime", but, I think, as a replay of Earth-616
history in full. But with some new characters, including
Ultimate ones. Other re-created universes exist, but
Ultimate Earth is gone.
There also have been several other Marvel stories where
the world was destroyed and then created again either
exactly the same or as good as. I think the wizard
Sise-Neg did it. The X-Men had an "Age of Apocalypse"
with history catastrophically altered while no one
else noticed. The Fantastic Four used the "Ultimate
Nullifier" to defeat Abraxas by destroying the universe.
"House of M" consisted of the mutant Scarlet Witch wishing
the universe was different, so it was. It got wished
back. Genis-Vell, son of Marvell, went mad and
destroyed the universe, again, then it got re-created
with a different history for /him/ but much the same
otherwise - in the new universe, his mother hadn't died,
/again/, and he has a sister. (Incidentally, they're
all from Saturn. I think.)
Meanwhile, Jewish Spider-Man cut a deal with the
Marvel Devil so that his marriage of many years never
happened, along with the exposure of his secret identity.
I am not making this up.