Grafting
This is the single most likely candidate for raw abuse and grossing out your fellow players. This Power is strictly Mad Scientist material (it does have its good side, too, though.)
The hero can perform psionically augmented surgery on a subject. The hero can operate on, dissect, rearrange, and perform transplants without the need for normal medical techniques to ensure success. No matter how crude the conditions in which the operation is performed or how messy it proves to be, the subject's lifeforce is preserved. There is no major blood loss nor is there any need for extensive recuperation. This Power is strongly related to the Healing forms of Bio-Physical Control and can be used to cure others of physical damage. Unfortunately, the Power lends itself to abuse. Those possessing this Power tend more toward Doctor Frankenstein than Doctor Schweitzer. Such characters might see people as machines to be rearranged at their whim. This Power permits the character to perform acts beyond 20th century medical science (like brain transplants). If 2 or more brains are combined, the resulting character shows traits of both.
The Power rank determines the success of the operation. A green FEAT ensures success of a routine operation, like simple surgery (anything that might be done at a clinic). A yellow FEAT is required for more elaborate work transplants, grafting, anything requiring a large hospital. Outright medically impossible acts such as brain transplants and body part rearrangement (after which all the parts still work-hands where feet should be, and that kind of thing) require a red FEAT.
Success means the result is alive; it may not be pretty, but it's breathing.
A hero with this Power will use it to heal. A villain will use it to fill his lair with a variety of ex-human nightmares.