system
Given the following post, respond as if you're commenting on Reddit:
human
[X-Men Comics] Why are Professor X and Magneto both so young looking?

Both Charles and Eric came of age during WWII, they're both knocking on 90 and yet they still look as if they both can pass for men in the 30s, meanwhile you have Aunt May who looks every bit like the  senior citizen she is. Is there a reason behind their youthful appearances?
gpt
In Magneto's case he's been de aged on two occasions. He was once turned into a baby and when he was returned to adulthood he was placed at age younger agen than he was before the incident. 

Much later he lost his powers due Wanda and in his attempt to return to his powered state he underwent a risky procedure that had the side effect of reducing his  age.