Arx Fatum Vilrex

History
Meaning "The Ark of Doom's Might", Arx Fatum Vilrex, the Fortress Monastery of the Heralds of Coming Doom was constructed on Borous Prime, the newly found home world of the Chapter.

Building work on the Monastery itself was started in the early 4th Century of M32 and took 76 years for the main systems and defences to be built and brought online, it took a further 47 years for the auxiliary systems and shrines and other immediately non essential systems and facilities to be finished. It was shortly afterwards that additional forest was cleared for the construction of roads, agricultural facilities and communication networks in anticipation of the construction of townships, mines and manufactories as the population of Bororus Prime grew as the Chapter brought more colonists to the planet.

It took a further two centuries before the first few towns were fully constructed and operational and able to launch mining and manufacture operations, the towns were heavily fortified, somewhat similar to the Vilrex itself due fears of attacks by native predators of the planet, considering it was a death world. The whole process of colonisation was slowed down by the attacks of wild animals on the Humans responsible for constructing the colonies. Only the combined efforts of the Heralds of Coming Doom and an Imperial Guard Regiment loyal to the Doom Heralds themselves were able to stop the attacks long enough for construction to resume relatively unmolested.

It would take a further several centuries for the construction to be finished as the population grew and more townships and mines were constructed as a result as the growing strains on the towns increased the potential levels of production increased.

The Psychic Masking array
It took the Seers of the Doom Heralds 20 years since the discovery of Bororus Prime to build a psychic device powerful enough to sheild the planet's presence from both conventional and psychic detection.

This the main reason why no one else knows of the location of Bororus Prime and Arx Fatum Vilrex. The array is a large structure within the techicarium within the main keep of the Vilrex and consists of a series of crystalline focusing chambers and a dispersing lens made of psycho active materials and supported and ran by ancient circuitry and cogitators. It is powered by a series of fusion generators and is constantly monitored by a mix of servitors, Tech marines and Seers.

It works by concentrating and generating vast psychic power and dispersing it in specific patterns designed to give nearby warp currents the "appearance" of those typically found around empty, desolate space. This process also creates radiation and ionised particles as a by product which can be used to scramble the conventional sensors on space ships.

Fortifications
The Arx Fatum Vilrex's defences include a wall 50 Metres tall and 20 Metres thick. This wall totally surrounds the Vilrex and every 30 metres along its length the wall is topped by a Vulcan Mega-Bolter turret and every 50 metres the wall is topped by quad-barrelled, high powered lascannon turrets. Behind the wall, the main keep and surroundings have numerous AA turrets (similar to those used by hydras) and Deathwind artillery pieces built into the roofs and battlements to provide anti-air and long ranged support.

The main gates are wide and over60 metres tall to allow entry of the Legio Artrexus' engines and allow for large armoured columns used both by the local Imperial Guard/PDF regiments and the Doom Heralds themselves.