X-Men: 10 Worst Things The Mutants Have Done
8. Beast Brings The O5 Into The Present
Dr. Hank McCoy is known as one of the X-Men's smartest members and has been indispensable to the team while even being part of other groups such as The Avengers. But despite his impressive list of credentials, Beast's decision to bring in the O5 X-Men would cause ripples throughout the Marvel Universe.
After Cyclops killed Professor X while under the influence of the Phoenix Force, he had become a revolutionary, which caused a rift within the mutant community. Beast then decided to bring the younger versions of himself, Cyclops, Marvel Girl, Angel, and Iceman to the present after seeing how far his former friend had fallen.
This causes trouble for years to come with the time-displaced team coming to terms with the terrible events that will transform them. The young Scott Summers is ostracized for the crimes of his future self, while Jean Grey is horrified by the deaths and hardships she'll experience with her encounters with the Phoenix.
McCoy's actions would even cause his allies to question his decisions, and though the O5 would eventually return to their time, Hank's decision would remain hated by the fanbase.