Soros, also known as the Black Hive, was a mythical hive of Killiks that resided on the planet Alderaan. They were considered more savage than the other nests and many Alderaanians feared them. The last time the Black Hive emerged, it left entire cities in ruin with its monstrous Killiks becoming more bloodthirsty for every Joiner they absorbed into their ranks.
At some point during the Cold War, the re-emergence of the Black Hive was discovered by Bouris Ulgo who had claimed the position of King of Alderaan. However, instead of alerting the Order of Extermination, he decided to hire mercenaries to handle this threat. It was believed that he was uncertain of the Order's loyalties in relation to House Ulgo which was why he embarked on this campaign. The mercenary company he hired were the Blood Company to fight the threat but instead were absorbed into the hive mind as Joiners where they spurned the Black Hive into violent action as their savagery along with knowledge was spread throughout the nest. This massive force of Killiks decimated the armies of House Qel-Nosh and House Antilles as well as threatened the House of Thul. This led to the Alderaanians to believe it was the Black Hive that had returned after a millennium underground.
Lord Serjay Thul recognized the threat that was posed by these Killiks despite him not believing the superstitions surrounding the Black Hive. He believed that it was the result of these savage Killiks which forced the other nests to emerge to the surface. The threat was unable to be combated by Thul in fear that this would weaken the house to allow their enemies to destroy them. Thus, he charged an unidentified Sith Imperial to ally with the Order of Extermination to eliminate the threat. Chanya Medaal worked with Thul's allies where she discovered that the threat came from the Joiners which were eliminated thus pacifying the threat.
- Star Wars: The Old Republic (First appearance)