An interesting feature of their culture is their apparent lack of space travel, as they rely on interplanetary Warp Gates they call "Tetragates" that are very similar in function to the Aeldari's Webway system.
At the time of the Age of Strife, the Saruthi inhabited over forty star systems centered on their homeworld of 56-Izar, including the subsequent human colony world of Damask. They encountered and dealt with humans fleeing Terra who possessed a copy of the Necroteuch. When this Chaos tome was translated into a form the Saruthi could comprehend, exposure to it irreversibly corrupted their minds, their culture and their physical forms, leading to the collapse of their empire in civil war.
This influence can be seen in the mutational deformation of their bodies and the disturbing asymmetry of Saruthi artefacts, such as the carvings unearthed by the human settlers of Damask. At the time of the so-called "Affair of the Necroteuch" in the late 300s.M41, contact with the Saruthi was prohibited by the Imperium of Man.
The heretical Glaw noble family made clandestine contact with the xenos race in an attempt to recover a human-readable copy of the Necroteuch, but the conspiracy was broken by the Inquisition in the person of Gregor Eisenhorn.
The Saruthi homeworld of 56-Izar was subsequently subjected to Imperial military assault and Exterminatus. No further contact between humanity and the Saruthi has been reported.
During an investigation carried out by Inquisitor Gregor Eisenhorn into the whereabouts of a powerful tome of Chaos knowledge called the Necroteuch, Eisenhorn made contact with these xenos on their colony world of KCX-1288.
The Saruthi Eisenhorn met used two of their hands to form a human face, which was fully capable of speech. In addition, they are able to shoot ice-blue bolts from a corona of electric-blue energy around their head.
At the time of Eisenhorn's visit, the entire system was self-destructing, its ancient star beginning to lose its molecular cohesion. The star system was strewn with debris, asteroids and clouds of deadly radiation. The third largest planet in the system was used by the forces of Chaos under the Renegade Inquisitor Oberon Glaw as a meeting place with the Saruthi.
The planet was as ruined as the rest of the system. A gaping wound in its crust led to an entry into the Tetrascape where the Traitor Inquisitor rendezvoused with the Saruthi.
It was here that Eisenhorn and his group of allies managed to destroy the Terran copy of the Necroteuch, along with killing the Champion of Chaos Mandragore of the Emperor's Children Traitor Legion and Oberon Glaw himself.
Five-limbed, with physical resemblances in human eyes to both arachnids and crustaceans, the Saruthi have no optical or auditory features (i.e.: no eyes and ears) but their sense of smell and taste are much more developed by human standards.
Their skin is grey and wrinkled and their bodies are asymmetrical, a mutational legacy of their association with the Terran tome of Chaos lore called the Necroteuch.
Their limbs terminate in metallic calipers which can perform manipulations or grip stilts to add to their height, a Saruthi cultural affectation. Their faces are oblong, lacking any sensory organs save for several olfactory openings. Saruthi perceive their environment through smell and taste and they have thus developed a fundamentally different view of the universe to a species that possesses vision in any frequency of the electromagnetic spectrum.
They have been observed performing a number of unusual feats, such as twisting their limbs into humanoid "faces," which can communicate with humans through speech, or projecting deadly energy of an unknown origin resembling lightning discharges.
Saruthi blood is a grey ichor and they stand around two metres tall, have about twice the mass of a man, and possess five appendages, placed in a seemingly random order across their body.
A smaller, paler variant of Saruthi, who do not use tools, seem to coexist with the "normal" Saruthi, although it is not known if these beings are another gender, a sub-species, a slave caste, a combination of these or something else entirely.
Saruthi cities are enclosed and from the outside resemble giant spiral shells.
The Saruthi are able to create portals through the Warp and artificial environments within the Warp, known respectively as "Tetragates" and "Tetrascapes," which allow them to inhabit a space outside the physical universe in the Immaterium and to travel interstellar and interplanetary distances with no need for starships.
Whether this technology was derived from studying the Necroteuch or was developed independently is uncertain.
- Xenos (Novel) by Dan Abnett, pg. 266
- The Inquisition: An Illustrated Guide to the Secretive Protectors of the Imperium, pg. 76-77