| Category | Marvels, Voidships |
| Type | Helas Vessel |
| Continent | Brucrumus |
| Region | Troll Bogs |
| Alias | Kythac Helas |
| Owner | unknown |
| Built | 28 Lunar 1795 DE |
| Map | Chen'gom |
The Spire of Rioch Tetrax is a Helas Vessel class voidship. In the Horgon Era, this primordial-built structure was on Osâchar. On that world it served as the palace for a Saint of Maen named Rioch Tetrax. In the Second Suellk Invasion, Osâchar was beset by an illithid invasion. In 537 HE, Helas Vessels left Osâchar and entered the Void. It was the end of Horgon (159 HE - 537 HE) civilization on Osâchar.
A little more than three centuries later, 862 HE to be exact, the Helas Vessel entered Bal-Kriav's atmosphere. One of these was the Kythac Helas; better known today as the Spire of Rioch Tetrax. It landed in the southwestern part of Chen'gom. It descended into Mount Orngrek, a dead volcano, the new home of its passengers. In an area of mixed light and absolute darkness, an area they named Tûnin-Gil, the Durkoth leader Rioch Tetrax and his Durkoth turned to nation building. Their center of power was based out of Nagdúrzol. The army of these new arrivals was several thousand storm archons called the Laupha. The support staff, the workforce, and soldiers when needed, were nearly 12,000 Dromite slaves.
Like other Helas Vessels, the Spire of Rioch Tetrax has an otherworldly appearance. It is powered by the psyche of Kythac Helas - a living sentient engine spawned in the Creation War by the primordial Beldileck.
A surface darker than the darkest nights. Under a torch, you can see the light bend towards the Spire. Sometimes this is so pronounced that magical light sources are smothered and torches and other mundane lights become near useless. On entering the Spire, all returns to norm.
- excerpt from the book "The Horgon Spires of Midrêth"