Clarifications
Initially, the Earth X storyline was purported as being the future of Earth-616. However, the series often substantially retconned the origins and workings of characters to better suit the story, to the point where they were no longer reconcilable with their counterparts in the mainstream Marvel Universe. One example was the revelation in Paradise X that Wolverine is not a mutant at all, but instead one of the few remaining "pure strain humans", free from the genetic manipulations of the Celestials (as well as a descendent of Moon-Boy). Marvel editors solved these discrepancies by officially declaring that anything stated in Earth X would not be considered canonical. It was also later revealed in issue #11 of Paradise X that the events shown in the series are not set in an alternative future, but rather an alternative present (the issue reveals that Paradise X is set in 2003, the year of publication).
The Paradise X series was never properly concluded, due to editorial interference midway through its publication. Due to dwindling sales, the X and A specials, which were intended to be double-sized issues, were both reduced to 22 pages and the intended ending was never used as a result. Writer Jim Krueger expressed dismay at the loss of pages and not being able to use the original ending. In the intended ending, Captain America, suspecting Captain Marvel's treachery, would have killed Marvel just as Marvel put the energy wall around the universe to keep out the Celestials and Elders. At this final moment, having ascended to the throne of Paradise, Captain America would have realized that Marvel's intentions were good. "Cap would have sat on the throne, completely unworthy of it. And this, this would have been the final testing necessary to make Cap worthy of it."
Additionally, a planned limited series, Tales of Earth X, was proposed but never greenlighted. The series, set before the events of Earth X, would have revealed the final days of characters like Professor X before the mutation that turned the world into mutants and killed all of Earth's psychics.
A one-shot called The Earth X Companion was released in 2008, containing production notes and sketches by Jim Krueger and Alex Ross as well as a short story drawn by artist Bill Reinhold detailing the fate of one of Nick Fury's Life Model Decoys.
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