Marvel Comics heard about the episode while it was still in production, and they liked it so much that they didn't just turn it into a comic -- they turned it into like 40 comics, making up the "Age of Apocalypse" crossover. Now, mega-long crossovers were nothing new for '90s Marvel, when every other issue had at least two storylines from other comics butting in and taking out pages from the character you actually wanted to read. What set "Age of Apocalypse" apart was that Marvel went all-in on the "alternate reality" part and replaced the entire X-Men line with new series set in that Xavier-less parallel reality as if the readers themselves had slipped through an inter-dimensional portal while walking into their local comic book store. Hell, some of the alt-series were better than the ones they replaced.
After four months of these new titles, Magneto's X-Men manages to send Bishop back in time to prevent Professor X's death, and the "Age of Apocalypse" timeline is erased from existence ... until Marvel decided that no, it wasn't, because people liked it. The "AoA" reality has been revisited multiple times through prequels, sequels, and spin-offs, and several characters who originated there have ended up moving to the regular Marvel Universe, like hunky Cable and Dr. Mengele Beast.Â
But the main legacy of "Age of Apocalypse" was pioneering a more immersive type of crossover event. In 1996, Marvel and DC pulled a similar stunt in the middle of their Marvel vs. DC series, right after an issue where the two universes are merged by cosmic forces. When readers walked up to their newsstands the following week, the only new comics waiting for them were set in the shared "Amalgam" universe, featuring remixed versions of characters from both companies. For instance, Spider-Man plus Superboy equals ...