Repsol is one of the engineers who built the machines that run The Plant, where Chrysm is used to grow "enhanced crops." Originally, Repsol worked with Palet on a machine that ran on Chrysm and Yggdrasil sap that was meant to bring the dead back to life. At some point, Respol is believed to have decided that there was nothing more unnatural than this sort of necromancy, and began devoting his research to using Chrysm to enhance the growth of crops. These "enhanced crops" eventually were declared dangerous by the King of Wyndia some time after Repsol's death. This occurred after several machines at The Plant began to malfunction, causing Chrysm gas to leak out of smokestacks and mutants to appear within The Plant and The Dump.
Although he is said to have been the greatest engineer who ever lived, having done extensive research on Chrysm, machines, and interactions between the two, he is also believed to be something of a pornography addict. This is evidenced by the fact that almost every shelf in his study atop The Tower is programmed with messages such as "Not for sale to minors" and "You see a collection of 'adult' books..."