10 Superheroes Who Broke Their Own Rules
3. Professor X Mindwipes Magneto
We all know someone who asks the question "if there are psychics, why don't they just mindwipe the baddies to be good or destroy their minds?" It's a fairly common complaint about heroes and morality that has been answered in books like Squadron Supreme or the awkward Identity Crisis treatment of not just Doctor Light and Batman having their mind altered but others, like Catwoman after she became a mostly-good girl. But boy did X-Men do it in a big way.
Charles Xavier has actually done this twice. A minor time that many like trying to forget, ironically, is the time that Xavier mindwiped everyone involved to hide that there was an X-Team in between the original members and the All-New, All-Different version from Giant-Sized X-Men #1. It was a weird retcon that answered the question of who the third Summers brother was and no one actually likes it.
The best example though, and the one really worth talking about is during the Fatal Attractions storyline. Magneto comes back from the dead to lead his Acolytes against the X-Men again, but this time Magneto seems out for blood, as he creates an electro-magnetic pulse that knocks out a most of the Earth's technology.
This, paired with the fact that Colossus has given up on Xavier's dreams and actually joining the Acolytes, and Wolverine's adamantium being ripped from his body, pushes Xavier to mind-wipe Magneto, leaving him in a coma. It is the one time that Xavier broke the 'no mindwipe" rule and actually felt bad about it.