Aaron was once one of the scientists who worked on the computer. He was in his late 30s, frail but extremly intelligent. He was very pale and thin because he spent all his time indoors and hated physical labor of any sort. He was rich enough to pay people to do anything physical for him. He lived in of the biggest cities of the time and was hugely successful. This was how he lived before. A good but empty life of luxury, science and money.
But these were just memories now from before the chemical release. After the incident Aaron's huge city became a savage jungle of towering trees and vile plants. Natural predators were far stronger than usual and some had strange abilities. The men who used to work for Aaron were now mutant creatures that lived only to kill. But Aaron had changed as well. The once weak, shut in scientist had been turned into an amazon boy by the chemicals. His small body grew smaller and younger. The pale skin became fresh and brown. He grew a ton of muscle especially for a little boy around 10. He also got a lot dumber to compensate. He didn't remember much science stuff, only how to hunt and survive. He loved being outdoors now and was afraid of being inside or around technology he also couldn't help but show off a lot. Instead of a lab coat he now wore a simple animal pelt to preserve his dignity.
Aaron lived day to day now, always fighting to survive and coming out on top thanks to his strength and hunting skills. He forgot more of his old life by the day and soon he would only remember being an amazon boy if he didn't find a way to reverse this quickly. He knew he had to find the other scientists who were likely also changed and hope that some of his knowledge came back so they could fix the world. But part of him didn't want to go back to that reality where he was a weak nerdy scientist and that part was growing with every kill.