Has a major villain ever truly reformed?

Has there ever been a major villain in comics who has reformed and stayed reformed? I know that Magneto has reformed a few times, but it never sticks.

Rouge is the first one to come to mind.

I don't know if you could consider Rouge a "major villain".

Emma Frost.

@Illuminatus said:

Emma Frost.

@Mercy_ said:

@Illuminatus said:

Emma Frost.

Magneto, he's a hero now.

Flash Thompson.