Desolous was a dark lord of the Sith who existed in the galaxy a significant amount of time before 35 ABY. The Sith Eternal organization, which operated during that time, traditionally named their Sith trooper units after ancient Sith figures. Thus, the Desolous Legion received its name from this figure – a name whose true meaning was hidden from those not part of the cult.
The initial mention of Desolous within current Star Wars canon occurred in Star Wars: The Rise of Skywalker: The Visual Dictionary. This reference work, released on December 20, 2019, served as a companion to the film Star Wars: Episode IX The Rise of Skywalker.
This character's origins are in the Star Wars Legends continuity. There, he was portrayed as a Pau'an Sith Lord known as Darth Desolous. He was originally created as an exclusive character for the PlayStation 2, PlayStation Portable, and Wii versions of the 2008 video game Star Wars: The Force Unleashed, which was developed by Krome Studios and published by LucasArts.
- Star Wars: The Rise of Skywalker: The Visual Dictionary (First mentioned)
- " The Final Order and the Battle of Exegol " — Star Wars Encyclopedia