Born outside of Los Alamos, New Mexico, Emily was the daughter to two highly regarded (and highly classified) researchers in the fields of radiation application medicines and mutations. At age 11, Emily discovered she herself was a mutant; a mutant her parents created by exposing Emily's fetus to extreme variations of radiation and mutagen solutions. At age 12, she was 'experimented' on by her parents as a lab rat. After weeks of grueling tests, Emily escaped and ran out into the New Mexico dessert where the nearest home or facility was at least 50 miles away.
While plodding through the desert, whenever Emily got tired, she'd rest and start to see a green glow emanate from her body and skin. After the glow, she felt refreshed and ready to carry on as if she'd just woken up, fresh as a new day. This occurred two more times until hours later, she found an old gas station and a kind old couple. They took her in, fed her and heard Emily's tale of being her own parent's lab rat. Horrified, they swore they'd take care of her. They called the police to assist. Before the police arrived, Emily's parents and several armed men arrived at the gas station.
They wanted Emily back and 'no' was not an option.
The old couple fought the armed men, shoving them out the front door of their house behind the gas station.
That's when the old man was shot.
Emily, shrieking is panic, flew to the old man's side to help him. When she touched him, she transferred her green glow from her body to his, healing his through-and-through gun wound as if it had never happened.
Emily's parents, ecstatic over what they'd just seen, voiced their demands for more tests back at the lab. As the armed men advanced to take her, Emily turned to them, angered more than she'd ever been, and with a red glow, drained the life essence from three of the four armed men, killing them instantly. She then started doing the same to her parents until the 4th gunman smacked Emily in the head with the butt of his gun.
As Emily's parents and gunman dragged Emily to their car, the old man broke out his shotgun killing the gunman and winging the father in the leg. Emily groggily crawled from the scene towards the gas pumps, trying to hide. The mother, fearless in her demeanor, took the 4th gunman's rifle and started shooting at the old couple. She hit the old woman in the shoulder and killed both the old man, just as the town sheriff showed up and shot the mother through the heart. As her last dying act, the mother wheeled around to Emily, curled up next to one of the gas pumps and shot in rapid fire, hitting Emily three times and igniting the gas pump, creating a cauldron of fire and flames shooting over a hundred feet into the air.
The only one remaining alive in all of this was the old woman, who was shot in the shoulder, the crippled father and the sheriff...that is, until a burning Emily walked out of the flames. In bands of green light. She'd healed herself with her new-found mutant powers. The father jumped in his vehicle and took off down the road. The sheriff put out an all points bulletin on him and went back to check on the old lady and Emily.
Emily's clothes had been burned off, yet she didn't have a mark on her. Emily went over to the old lady to heal her and did so, however, when she tried to revive the old man, she wasn't able to.
He was dead.
After everything settled down, the sheriff took Emily and the old lady back to the police station. The father's car was found at what once was their lab facility, but now, it was nothing but a smoldering ruin. Indications of a helicopter lifting off from that site prompted the investigators to believe the father and one other person had flown off in a helicopter. Emily's father and the 2nd person were never found.
Emily was adopted by the kind old lady and was raised by the town folks. In turn, anytime someone got hurt, she helped heal them As a result, the town folks grouped up some of their savings and helped send Emily off to college to become a doctor. Six years after she was sent to Yale University Medical School by those kind folks, she became a doctor.
For the next few years, Emily was involved in dozens of incredible adventures and dangerous situations, each time saving the day with her powers and/or her medical skills. During one such event, G.U.A.R.D. had been involved. She'd saved dozens of guardsmen and women from certain death in a super-villain battle. As such, when she was asked if she'd to join GUARD, Emily agreed to join them.
To this day she is known as Dr. Emily Tashun (Tashun being the old couple's last name), however, most in GUARD know her by her code-name: Dr. M.U.Tation!