The technopathic human-Sentinel hybrid Bastion appeared in X-Men 97, but he almost debuted in a canceled X-Men animated ...
Stan Lee was tricked into going against a Marvel mandate for X-Men: The Animated Series, and the ruse has saved the series.
The X-Men have called some of the most formidable mutants members, with the team fielding numerous Omega level mutants.
Many of Tony Stark's most advanced Iron Man inventions from the comics could still revolutionize the MCU even though Marvel overlooked them.