Viskeons are a warrior xenos species in danger of extinction.
Viskeons are a vaguely humanoid, blue-skinned and cold-blooded alien race, able to spit acid, absorb energy during the heat of the day in order to move with mercurial speed and vicious strength during the night, and to regenerate wounds even after losing entire limbs.
The Viskeons originally came from an unnamed, hot and parched homeworld, located somewhere in the Ultima Segmentum that is wreathed in endless deserts, impenetrable jungles and sweeping plains, perfect environs for a cold-blooded species.
During the Second Tyrannic War, however, an Ork fleet (that had been manipulated by events set in motion millennia before by Eldrad Ulthran) smashed unwittingly through one of the Tyranid fleets that had splintered from Hive Fleet Kraken after the Battle of Ichar IV. This made the Tyranids radically altering their course, turning towards the Viskeon home world instead of their original destination -- the Aeldari Maiden Worlds.
The skies of the Viskeon homeworld boiled purple as millions upon millions of Mycetic Spores hurtled through the atmosphere, disgorging a multitude of hideous alien monstrosities. The planet died in a single night's violence.
Without ranged weaponry, the sheer number of rapacious alien predators swiftly overwhelmed the Viskeons.
In less than ninety solar days, the hot, dry world was reduced to an airless ball of dead rock, stripped of every single organic component.
Save those who had been fighting on other worlds as mercenaries, such as bounty hunter Krashrak the Stalker, the race of Viskeons had been exterminated.
Viskeon culture was suffused by a strong sense of martial honour, and their warrior code did not permit the use of ranged weaponry. To face an opponent in battle, blade-to-blade, was the supreme honour one warrior could pay to another. Anything less was unthinkable.
The young warriors would frequently leave their homeworld to fight and prove their mettle before returning home. Many of the Viskeons plied their trade across the galaxy as mercenaries, bounty hunters and the like, and their skill at arms was highly valued.
- Games Workshop - Inquisitor: Kashrak the Stalker
- Xenology (Background Book) by Simon Spurrier, pg. 81