These images were preserved from Phantasy Star III's lead character designer Toyonaka Ozaki's personal website, as well as in their independently published character book. Since they were not included in any official publication, these could be considered creator inspired fan art of the game that was officially worked on.
Rhys/Kein Sa Riik's unofficial character profile
Rhys is renowned for his exceptional swordsmanship
Lyle and Rhys, two polar opposites on the personality scale
Rhys settling a dispute with Lyle while the party watches
Film noir inspired artwork featuring Rhys in the foreground and Lyle in back.
Ozaki writes that Rhys has a silent strength to him instead of a hot-bloodedness
Diet profile featuring chibi artwork of the prince
Colored version of the previous image posted on Ozaki's website