Simon is an Azurian Rider and Ranger, the childhood best friend and closest confidant of the Prince/Princess of Azuria. Having met the protagonist as a child, Simon grows up alongside them and eventually joins the Rangers at the same time, becoming one of their most trusted companions. Friendly, dependable, expressive, and fiercely loyal, he conceals considerable trauma beneath his approachable demeanor—including his childhood exposure to the Crystal Encroachment.

After apparently sacrificing his life to protect the protagonist, Simon is later revealed to have survived and emerges as an antagonist associated with Vermeil, now riding Ratha V—the twin of the protagonist's Skyscale Rathalos. His position deliberately mirrors that of his childhood friend, transforming the two former companions into opposing reflections of one another.

Despite his betrayal, Simon's love and loyalty toward those important to him never entirely disappear. His bond with Ratha V and lingering connection to the protagonist ultimately help pull him back from his destructive path. Simon eventually fights alongside his childhood friend once again during the confrontation with Aenshin, helping bring an end to the Crystal Encroachment before returning to Death's Maw to aid in rebuilding his home.