Evolution is one of the central ideas that the X-Men and mutantkind as a whole are built around, and right now, the X-Men's world is evolving at a rapid pace. In just a handful of issues, the ongoing interconnected miniseries House of X and Powers of X have completely upended everything about Marvel's mutants.
Through the living island Krakoa, Professor X has formed an isolationist mutant nation that stretches from the Earth to the Moon. The X-Men are working alongside their oldest foes, long-dead characters have reappeared with no explanation and some of the X-Men's most famous members have just been killed off.
Still, all of that pales in comparison to the story's revelations about Moira MacTaggert. The longtime X-Men ally has secretly been a mutant with reincarnation abilities that give her 10 or 11 lives. Every time one of Moira's lives ends, she dies and is reborn in a new timeline with all the memories from her previous lives.
Using that accumulated knowledge, Moira has tried (and failed) to save mutantkind from the apocalyptic future that it seems perpetually destined for. In Moira's tenth life, she showed a young Charles Xavier--and later Magneto--all of her memories before the formation of the X-Men in a twist that seemingly reframes the team's entire history.
But given the story's game-changing revelations and complex structure, it's not entirely clear whether or not the main story of House of X even takes place in the main Marvel Universe.
WHY HOUSE OF X COULD BE IN THE MARVEL UNIVERSE
Both House of X and Powers of X reveal key information through text-heavy data pages, like the timelines that chronicles key events from Moira's various lives in House of X #2 and Powers of X #3. While a few of those timelines featured one or two familiar ideas, the events of her tenth life are the only set that matches up with established Marvel history, especially after Hickman made a correction to the initial timeline.
Among other things, Moira's tenth life is seemingly the only one where she had a child who became Proteus, an established X-Men villain who is an ultra-powerful Omega Level mutant. House of X has also featured data pages that include lists of Omega-Level mutants and major crimes against mutants that also line up with established Marvel history.
The series also has a few connections to the modern Marvel Universe. When Cyclops met the Fantastic Four in House of X #1, the team was wearing their current uniforms and discussed the Thing's recent wedding to Alicia Masters. By that same token, Wolverine wore his new House of X costume during his recent team-up with Captain America in Wolverine & Captain America: Weapon Plus, where the events of House of X went notably unmentioned.
WHY HOUSE OF X MIGHT NOT BE IN THE MARVEL UNIVERSE
The major status quo shifts from House of X have not been reflected in the larger Marvel Universe in the X-Men's guest appearances non-mutant comics. From the establishment of a new mutant nation to the deaths of high-profile heroes like Wolverine and Cyclops, these are the kinds of events that usually reverberate around Marvel's grand inter-connected narrative. But even if those deaths are immediately undone, House of X retroactively changes a huge chunk of Marvel history in a way that few, if any, stories ever have.
If Moira, Xavier and Magneto all shared information about Moira's past lives and what could happen next, that retroactively casts every single story involving Professor X, Magneto or Moira in a different light. For example, Xavier may have sent X-Men into battles where he knew they would die, and Magneto could've simply been play-acting as a villain as he quietly worked with Xavier for decades.
While Moira's tenth life shares several similarities with the Marvel Universe, that’s not a guarantee that they're the same timeline. As House of X #2 revealed, Moira's fourth life shared several similarities with the Marvel Universe, even with things as minor as the costumes that various X-Men wore over the years.
WHAT ELSE COULD HOUSE OF X BE?
If Moira's tenth life doesn't take place in the main Marvel Universe, then one of her other lives has to. With all of the information in the timeline, only Moira's sixth life and potential eleventh life are unaccounted for. However, House of X explicitly takes place in Moira's tenth life and relies on information that was gathered in Moira's ninth life in Powers of X.
Although Moira's sixth life will almost certainly come back into play in some capacity, the evidence either points to the Marvel Universe being part of Moira's theoretical eleventh life, which we know nothing about, or her tenth life, as depicted in House of X.
Both House of X and Powers of X are telling a complex, intricately plotted story where information is being doled out in a very specific sequence. In these miniseries, a single sentence can completely reframe everything that's come before, and this story is only just past the halfway point. While the series will probably make a few more shocking revelations, the current evidence suggests that House of X and Moira's tenth life take place in the Marvel Universe, for the moment at least. Although that may very well change as details about Moira's other lives are revealed, House of X appears to be the X-Men's next radical evolution.
Powers of X #4 releases September 11.