I Will Survive
Though the Ultimate Universe was destroyed, several of its inhabitants were able to survive the end of Secret Wars and found themselves with new lives in the Prime Marvel Universe. Most notably, Miles Morales and his extended supporting cast were transplanted into what was once Earth-616. While Miles himself has memories of living on another world, the rest of his friends and family don’t seem to know anything is different.
The Maker — Earth-1610’s super-villain Reed Richards — also survived the transition and resurrected his Captain America, Iron Man, Hulk, Giant Man and Wasp to fight Galactus’ Ultimates. Those characters presumably still exist somewhere in the Marvel Universe, having regained their memories and siding against the Maker. Jimmy Hudson — the son of Wolverine — joined the time-displaced X-Men to fight against a new team of Marauders comprised of Ultimate Universe mutants, while the hammer of Ultimate Thor crossed dimensions and was wielded by Volstagg, who became The War Thor.
However, thanks to the events of Spider-Men II #5, we now know that the Ultimate Universe is once again out there. More importantly, we've learned that things have moved on since we last saw it. There’s a new team of Ultimates that finally includes Peter Parker among their members, along with an Ultimate version of Ironheart and a resurrected Captain America, Thor and Giant Man.
It remains unclear as to whether Marvel has any further plans for the new Ultimate Universe, or if it was more of a proper goodbye to the Ultimate Universe from Bendis and Bagley, but either way, its return has major ramifications.
The Ultimate Universe’s return is most likely thanks to the Future Foundation of Earth-616, who chose not to return to the new Prime Marvel Universe and instead ventured into the now empty Multiverse with the Molecule Man to bring back the dead and forgotten worlds. Working together, Franklin Richards creates the worlds, which are anchored by a slice of Owen Reece’s self — which remains the same across the multiverse — then placed into the infinite by Mister Fantastic.
We recently saw Franklin and Valeria Richards at the end of Marvel Legacy #1, with the latter feeling somewhat homesick for her native reality. The lack of the Fantastic Four is seriously being felt in the Marvel Universe right now, with Moon Girl doing her best to live up to the legacy of Reed Richards and The Thing doing his best to keep Johnny Storm from self-destructing. It seems that Marvel has a plan for the return of the FF, we might not see it for a while.
As for the effect the Ultimate Universe has on the Prime Marvel Universe, we now have two Miles Morales’ living in the opposite universes. Key here is that the heroic Miles doesn’t know that his home dimension — which houses many friends that he believes died in the Incursion — has been recreated. The same goes for the likes of Jimmy Hudson as well, and the resurrected Ultimates who have been replaced in their own timeline by doppelgängers. Marvel’s Multiverse has always been a lot more fluid and less ordered than DC’s, but ever since Secret Wars it has felt more chaotic and unregulated. The official return of the Ultimate Universe indicates that this is by design and may just be building to something big in the very near future.