The most infamous victim of the Zaryn World Cleansers, the world once only known as Soleia IV was once the homeworld of the Soleians, a group of sinister merchants that discovered the Zaryn homeworld and threatened the species' homeplanet for a nonstop payment of credits. The Zaryn delegation, knowing what this would mean, elected to employ their World Cleansers, who are used typically only in emergency situations.
The Soleian kept their vessels orbiting the Zaryn homeworld for 3 full years. Sneaking the World Cleansers aboard one of the Soleian starships bound for refueling and restocking of food and water supplies back on Soleia IV, the crew had no idea that they were sealing the fate of their species. With the World Cleansers now stationed on the planet, they quickly began "cleansing" the entire world, while at the same time slowly removing the water supply to the absolute minimum to keep the Soleians alive; the Zaryns instead used the remaining water to keep their own numbers alive, and to send back to their own homeworld for use as supplies on their own ships.
With only 50 World Cleansers existing at any given time and the Soleian population numbering into the billions, it took the World Cleansers approximately 30 years to cleanse the entire world. By this point, all of the water had been smuggled off-world, and the blood that had been spilled had successfully overflowed, and replaced the old oceans. Few species were capable of adapting to life without water, and most species went extinct. Those to survive were mostly hemophagic reptilians and the like, but these were few and far between. This world quickly became known as "Soleia IV: The World of Blood", but this eventually was just shortened to "Bloody Soleia IV", and finally, the planet was officially renamed to "Blood". No races chose to take up residence here, due to the horrific scene of the oceans of blood. This led to the planet becoming the secret training grounds of the Zaryn World Cleansers years later.