Cathorso is (or was) a member of the retinue of the Traveler of Roads Untrod. Traveling with the Traveler, he and his men engaged in Alien tech salvage on the top floor of Skyfall delve. There, he and his fellows engaged in a brief alliance with the Mourners of Saerun Road before turning on them when reunited with the Traveler of Roads Untrod.

Despite his fighting prowess and scavenged Space Alien tech, he was swiftly killed by the combined might of the Shields of the Sorrowfell and the Mourners of Saerun Road.

Image retrieved from http://mandrakil.deviantart.com/art/King-s-Guard-213018888 on February 19, 2014.