What Happened To Everyone Who Used Cerebro?
7. Emma Frost
Emma Frost started out as a villain, but in recent years, she came over to the side of good. She didn't just try being a good person for a period, this former villain has taken up such a significant role in the X-Men that she has even led the team in place of Xavier.
She is also one of the more powerful telepathic characters in Marvel Comics and even has the ability to transform her body into diamond, which makes her immune to telepathic (and most physical) attacks. When she came over to the X-Men and took up a leadership role, she found herself needing to use Cerebro from time to time.
While she has sat in the chair and used it to locate other Mutants, her ability to detect and resist Cerebro is far more fascinating. In X-Men: First Class, she was able to detect Professor X's attempts to locate her and rebuff them.
She could even tell that Cerebro was turned on from thousands of miles away, which make her one of the more sensitive telepathic characters in the X-books. In terms of using Cerebro, she has done so on numerous occasions without suffering the painful feedback some lesser minds have experienced.