The cover alone convinced me that this was likely to be an interesting alternate world! :D
At the end of the Asgardian Wars Loki gave the X-Men and New Mutants a choice, stay in Asgard and keep all that they had achieved there, all the new lives and new loves they had found, and in the case of Storm, powers returned to her, or return to Earth as they had been before they arrived; Storm would be powerless, Magma would be human instead of the elf-form the elven folk had curssed her with, and so on (The only exception he made, out of
Of course, in the mainstream MU, the choice to return to was made, but this IS a "What if...?"
( ...all things are possible )