The Baron Rubix, an Ore-duke, held dominion over a delving citadel situated on the planet of Shu-Torun. In the course of the War on Shu-Torun, a conflict where Rubix and his fellow ore-barons mounted a rebellion against Queen Trios, who had the backing of the Imperial forces, Rubix dispatched his ship, the Lava Leviathan, with the intent to kill Trios. This assassination attempt targeted the ancestral retreat belonging to the Shu-Torun royalty, a location revered for its sanctity and tranquility. The mission failed, resulting in the leviathan's destruction, and prompting Trios to implore her Imperial allies to obliterate Rubix's citadel as retribution for his sacrilegious act.
The initial reference to Rubix's delving citadel appeared within the pages of the comic book Darth Vader (2015) 17, a work penned by Kieron Gillen and made available to the public in 2015.