He was four when he came into being, created by Mike to protect him. He did so unconsciously, not even knowing he was alive. He saw through Mike's eyes, and felt Mike's pain. He never thought about it, but if he had, he would have decided he was Mike.
He was seven when he woke up. He opened his eyes and saw that he was his own self, not a part of Mike. Not anymore. His ideas, reactions, thoughts, his simple sense of existence was different. He enjoyed thinking for himself, and did it as much as possible. Eventually, the long hours of thinking made him see his purpose: faceless, nameless protector. A human shield. Noble as it sounded, he came to resent it.
He was eight when the others started appearing. He had protected Mike to the best of his ability, but it hadn't been enough to prevent his identity from further splintering. The new presences were loud, and seemed to only think of themselves. They had a different way of protecting Mike: Instead of staying and bearing the pain, they would run away. He thought they were weak and uncaring, but Mike noticed them first because they spoke more. They all had names. He didn't have a name.
He was ten when they left their house. He didn't know what happened or why. He only saw the painful moments that Mike had never learned to deal with. As far as he was concerned, life's only constant was pain. The new house was happy, so he saw very little of it. Mike started needing him less and less, until he couldn't remember the last time he'd seen the outside world. Free of responsibility, his anger had nowhere to turn. He bottled it all up for years, until there was too much to safely restrain.
He was twelve when the suppressed anger became too much to bear. He knew it would happen, and he had trained himself to turn the anger to pure power. Taking advantage of the power surge, he forced himself into full control. Finally, he could experience the world. At first, the lack of pain disoriented him, but he learned to create his own. It didn't matter who suffered, as long as someone did. Life was all about pain, after all, and he happened to enjoy life. Somewhere in the endless cycle of pain, he created an identity of his own: The Malevolent One, or just Mal. His constant pursuit of suffering drove him to criminal ventures: He stole, lied, burned and dispensed pain wherever he could. It didn't last long. Mal had never even known any form of law existed in the world, so he had never thought about secrecy. The police quickly found him, sending him to juvenile detention with the promise of real jail on his eighteenth birthday.
He was thirteen and a half when the legal system changed their minds. They decided that the strange child who talked to himself (well, to Mike, but they didn't know the difference), frequently overpowered inmates twice his size, seemed to have a fascination with pain, regarded other people as toys to be played with and broken, drew pictures on his wall with his own blood, and constantly whistled the same song to himself probably didn't belong in juvie. They said that "a more mentally focused facility may cater to your needs more effectively". Mal knew what they meant: They were taking him to the madhouse. The word evoked images of a tumbledown mansion full of hopeless nutcases, usually treated with methods such as restraints and electric shocks. To Mal's disappointment, the "madhouse" was a highly advanced and humane mental hospital, with a 24-hour watch to prevent him from harming himself or anyone else. They had a hundred different methods for sneaking pills into their patients' systems, intended to start repairing their shattered minds. Mal resisted the treatment for as long as he could, until the nurses gave up and started forcibly injecting them into his bloodstream.
He was fourteen when Mike freed himself. Weakened in mind and body by the cocktail of sedatives, he couldn't stop Mike from reclaiming what was his. It didn't matter, anyway. Mal was too tired. Let Mike deal with it, he decided as he sank into unconsciousness. As he slept, Mike carefully locked him into a corner of the subconscious and threw away the key. Gradually, Mike forgot about Mal, believing him gone forever.
He didn't know how old he was when he woke up. He could have slept for an hour or a year, it was all the same in his cell. He quickly grew to hate the tiny prison. Juvie had been fun, and while the mental hospital hadn't been a picnic, at least he had things to do. His subconscious prison was barren as a desert... No, it was even more barren. Deserts had sand, but this place had nothing. It had been a mistake for Mike to deprive Mal of enjoyment. With nothing else to focus on, Mal only thought of two things: escape and revenge.
He was seventeen when he was released. Mike certainly hadn't chosen to release him, but head trauma did all kinds of weird and wonderful things. Mal had just been sitting there when a calamitous earthquake had shattered the walls around him. The first thing he did was seek out the other personalities, binding them in the strongest chains he could manifest. Most of them simply accepted their fate, begging Mal not to hurt them too much. Some of the stronger, more developed ones resisted, but none of them could stand up to Mal. Once they were all out of the way, Mal concentrated on Mike. The others could live on as his slaves, but Mike had to be eliminated. He didn't deserve to keep living, not when Mal had lived so much of his life for him. Did the world need someone who couldn't even deal with normal emotions without hiding behind a stronger persona? Mal deserved their body far more than anyone else, and he intended to take it.
He was still seventeen when Mike pressed the "reset button". Mal had been sure that Mike would give up, but the weakling had turned out to have a spark of courage. He had even released some of the other personalities on his way to the tower. Mal hadn't thought Mike would ever reach the tower, but just in case, he had installed his own personal insurance policy. When pressed, the button appeared to clear the mind of alternate personalities, but it only exiled them to another part of the subconscious. All in one place, they were even easier for Mal to subjugate for the second time. Free to roam the deepest recesses of Mike's mind, he planned carefully. This time, he wouldn't make any mistakes. The next takeover would be the last.