From Cassius Comics

A mutant who was abducted and had her brain surgically removed by the Third Species, Martha Johansson existsas disembodied grey matter in a protective jar. She was used as a weapon by Sublime in his assault on the X-Men until she rebelled and telepathically forced him to leap out of a skyscraper's window, destroying his physical body. Johansson was brought back with the heroes and became a student in the Xavier Institute's remedial class, tended to by her caretaker Ernst. When the class was transformed into the new Brotherhood by their teacher Xorn (who was impersonating Magneto), Johannson joined as well, although whether it was intentional or merely incidental with Ernst's induction is unknown.

Johansson possesses powerful telekinetic powers which she can use to keep a number of powerful-minded people unconscious at one time.