It is unknown just when Edmund was born, but he has been around for a very long time. It was long enough so that mutants weren't as widely known about as they are today but, were still not unheard of. From the beginning he was a weak and sickly child, always catching one thing or another. He first discovered his abilities at the age of six, when his older sister, Elizabeth came down with a very harsh fever. With his record of contracting every little sickness he was barred from seeing her. Edmund grew distraught as time passed on and Elizabeth would not get better but, fortunately she would not get any worse either, but, still no treatment seemed to hold any effect.
Stranger yet, the weaker his sister became, the stronger Edmund would get. Fearful he would lose her and not caring that he might catch this strange illness, Edmund sneaked into her room. The moment he had stepped into her room, everything became clear. He had power. He could feel her sickness; he could even see it clearly in his mind and what it wanted from her. She had power too.
Even though Elizabeth was unresponsive to everyone, Edmund found he could still communicate with her. He moved to Elizabeth's side to brush some hair from her face, and on contact it happened. They weren't in Elizabeth's room anymore. No, they were in this wonderful field with flowers and sunshine. Even better, Elizabeth did not show any signs of the illness that she had just moments prior. This Elizabeth was even unaware that she was sick. When questioned she admitted to her brother that she had powers; her vision and hearing were much sharper and more acute than they should be. She could tell that the illness was attacking her for them, she didn't want to let them go and Edmund had no control over his powers. The illusionary realm they were in faded as their worried mother forcibly pulled Edmund away from his sister. He was then confined to his own room, but that didn't stop him from visiting her in the mysterious mind world.
Their powers may have been vastly different, but even so, Elizabeth was able to teach Edmund some control over his. The disease she suffered from did come from him, but with Edmund having no idea how to use them they didn't advance beyond the simple, yet persistent fever. He couldn't entirely remove the disease, but this being his first encounter with his powers; it would not run its course without Edmund giving it that final push. Elizabeth still wasn't getting any better and Edmund feared that the disease would kill his sister. The young mutant wondered why just wouldn't she just give up her powers to it and get better. Edmund tried to direct the disease to her powers, only then to discover that aspect was not entirely up to him in how the sickness progressed, the disease's victim also had a say and Elizabeth had discovered a third way out of it.
Elizabeth emerged from her fevered sickness not only with her powers, but also with them enhanced. A little too enhanced; her eyes and ears had become incredibly sensitive, even more so than they had been prior to her getting sick. A mostly silent and dimly lit room was almost too much for her to handle. She had to learn control over them all over again. Soon enough their parents were aware that Edmund and Elizabeth had powers, and seeing Edmund as a threat, he was sent away to a place for people like him where they would not have to deal with the monster.
Edmund's new home was basically a boarding school with a number of mutants in it. This was where Edmund's change into a villain began. While in his new home, Edmund soon learned more about his ability, for one thing it would only affect people with powers, the normal kids there were apparently immune. For another thing, when someone would fall ill he felt his strength increase and came to enjoy the feeling to the point where he would even torment and provoke his victims in the mind world. He became addicted to the feeling of power and the strength that their losses gave him. It didn't help that the ability itself was so subtle his teachers and caretakers even doubted that Edmund truly possessed powers. Even believing that there was no connection between Edmund and the illness at all, thinking that the mutant children were simply not as clean or hygienic as the normal, human ones.
The first people to die because of his disease didn't happen for a few years (it seemed that not everyone to come down with it would give up their powers or trade for them so readily.) The deaths were seen as flukes at first, still no one really believed Edmund had a power, as his mutation wasn't nearly as visible as others' were (as there was a rise in physical mutations from survivors who had kept their powers within the school. So physical differences, which at the time Edmund had none had slowly become synonymous with mutant.) Instead of feeling horrified that he had caused deaths, Edmund was fascinated and had enjoyed the feeling he received, even reveled in it. The deaths had filled him in a way that the survivors never had. Luckily for him the deaths were blamed on a regular if brutal fever, until the father of two dead students arrived. He was a telepath and knew right away that something was off.
By this point Edmund's mind and even his body had become twisted, as his maturity had brought along more the more physical aspects of his powers. He had eventually left the school in pursuit of stronger mutants, his fellow students and children were no longer appealing to him. Edmund grew more arrogant and cocky in his choices, deliberately searching out more and more power. A tiger-morph here, a weather controller there he did not care, they we just prey to him.
Not all of Edmund's later encounters would end in death for his victims, but significant amounts were beginning to fall to it as he increased the dosage of his virus. Edmund had learned through trial and error that he benefited more from those who died than the other results. Unknown to him yet, but he had also gained a stalker of his own. Edmund had been faced with people coming after him before. In the intervening years he had become increasingly well known amongst mutant communities. Some were after him in hopes to increase or be rid of their powers. Others wanted to get rid of him, which was easier said than done if you were a mutant. He had ways of defending himself and if things got too rough, his powers would protect him and had even saved him from assault many a time. Even the occasional mutant out for revenge against him could be stopped, true he knew he could not re-infect someone, but he still maintained links of varying strengths with those he did and so had ample warning of their presence.
One mutant found a way around that strength. This mutant had not contracted Edmund's illness through Edmund himself. Apparently the disease was contagious, and without knowledge of his own deliberate infestation, Edmund was clueless that he'd be unable to infect this person. As stated earlier, a mutant could only catch it once. The day that the telepath, Alistair had come down to the school because of his loss, he contracted the sickness. Alistair survived it with his powers intact and incredibly amplified, but he had become grossly disfigured. Edmund's appearance was greatly changed as well, his facial features were little more than slits and his skin had taken on an almost translucent cast, the veins clearly visible beneath it. But these changes just made identifying him all the easier. Their fight was rough, Edmund, even with a boost in his strength from his victim reserves was starting to fail against his adversary. And worse, Edmund was visibly shocked when he discovered that his illness would not affect his stalker. Still worse, being of telepathic ability, Alistair had some kind of a hold on his mindworld. The final straw in the eyes of his opponent was Edmund's lack of remorse, yes those first deaths he caused had been entirely accidental, and the virus creator had indeed felt something akin to remorse, purely because they had been children, but such was not true for the subsequent ones. Edmund enjoyed it.
Edmund had to be stopped, and killing him seemed to be the only answer, but maybe there was another way. This mental mutant's powers had evolved to the point where he could strongly affect another's mind. He wanted to make Edmund suffer. The telepath made Edmund believe he had come down with his own illness. Alistair, thinking it to be a good and fitting punishment, tricking Edmund into killing or depowering himself. He did not count on Edmund having such a strong attachment to his powers. Like many other mutants before Edmund who, when faced with the ultimatum, was confused, and especially so, he believed that he was safe from his own powers, and rightfully terrified. Edmund took off running, heading for somewhere he would be safe to fight off his imagined infection.
Edmund made it to what he believed to be his sister's home just in time for the fever to render him unconscious. The telepath's revenge had worked, but in a more horrible way than he had intended. The telepath had wanted to strip Edmund of his abilities but, Edmund's panic was too much and the result triggered a new mutation within him. It was just as if Edmund had truly had come down with his own disease, the fevered mutant's powers became twisted and corrupt. Edmund began to shrink, his clothes and even his skin sloughing right off. Vomit, sweat, more skin, Edmund's mass just kept decreasing but, at least he was somewhere safe. Or so he thought.
Alistair had followed the ailing mutant, still managing that hold on Edmund's frenzied mind, the telepath's desire for revenge, driving him to see Edmund's punishment all the way through. Torture is the only way to describe it. Though Edmund's size was decreasing quickly, he had a long way ahead of him. During Edmund's more lucid moments, Alistair was there taunting him, hurting him. Whether in person or the mind realm Alistair delighted in teaching Edmund Fear. Squeezed in Alistair's fist and later between two fingers until he cried, spat on, flung about with telekinesis. The mental jabs were even worse, Edmund could not tell what was reality and what was on the minscape. Constant reminders of what he had lost the fact that he could be crushed by a single finger, he could be killed and eaten by a mouse. He was what he spread, filth, a disease, and completely helpless, then, soon afterward, though not Alistair's intention, broken.
That was when Alistair stopped. Edmund had stopped rising to his bait, even stopped his screaming. The minute mutant remained laying where Alistair had left him. Waiting to be finished off, he was still alive but unresponsive. Nausea filled Alistair following a peek inside Edmund's mind. The other mutant was nearly too small for him to get a clear reading from, without resorting to forcing the connection open. Alistair understood the feeling of power now, what Edmund sought on the release of his disease. He'd leave Edmund alone now. The now tiny mutant was still shrinking. Alistair did what he could to get Edmund's mind towards healing and took him to his sister's house, the place he kept crying out for. Wishing to at least give him sanity and comfort in what must be his last moments.
But, the damage was done, the seed was planted. With his sister's help he managed to not only recover from the ordeal and survive, but thrive at his new size long enough to discover new abilities that would aid him in his new world, his parasitic abilities. First discovered when a rat drank the saucer of water Edmund had been resting in, his skin, needing to remain moist in his altered state. Once within the rat's body, the filaments emerged from Edmund's spine and everything came naturally to him. Soon after an epiphany followed; Alistair may have taught him fear and tortured him, but the telepath had also opened his eyes. Edmund now knew that he had been using his powers the wrong way the whole time. He'd been using them soley for personal gain and had been punished accordingly. But, in that punishment he had obtained his true form and realized his ultimate power. Edmund would now use his powers differently, as they were meant to be used, and teach others the same.