“...Canon.”
Reality is running wild as Mysterio has been using Florida swamp water from Man-Thing's back yard in his special illusion gas causing villains and heroes to appear who should not exist in the time of the original X-Men. A group of comic readers who have been getting funny books from the future for years (thanks to a Diamond warehouse sitting in a reality nexus) help the X-Men battle Mysterio and put things back to the way they should be.