Guiltythree is the pen name behind Shadow Slave. The author’s official website describes a classical education followed by a career in game writing and narrative design, before a move into progression fantasy.
There is another published novel to explore: Free Fall (Pyramid of Gold). On the author’s Webnovel profile, Guiltythree says it was written before Shadow Slave and that lessons from that first book informed the later project. Free Fall’s official synopsis follows a genetically altered protagonist whose abilities make him a target.
Sunny buys a coffee he can barely afford, then goes up a mountain where a sword costs more to carry than it is worth. Over twelve chapters, Guiltythree gives a poor boy an exacting eye for the price of things, including other people's help.