K'ara

K'ara, known to the orcs as the Dark Star, was a naaru who came with the draenei to Draenor aboard the Genedar.

Flight of the draenei
During the Genedar's crash several centuries ago, K'ara was injured, which caused it to enter the Void state of the naaru lifecycle. K'ara's final act was to convince the draenei to eject it from the vessel, but this was easier said than done. The Void energy instinctively caused K'ara to go to war against the other naaru aboard the vessel, D'ore and K'ure. Their violent clash of Light and Void threatened to kill any draenei who interfered, yet Prophet Velen stepped forward nonetheless. He used the Light to shield the other naaru and cast K'ara out of the vessel. But the battle sapped his strength, physically and mentally, and his visions of the future became unreliable. K'ara was ejected from the Genedar in the chaos of the crash, and came to be known as the Dark Star to the orcs of Shadowmoon Valley. Because of both the Void's power to defile the dead and that those few who accessed K'ara's shadowy power directly had their minds shattered, the ancient chieftain of the Shadowmoon clan outlawed its powers after the discovery of the Dark Star.

Rise of the Horde
During the rise of the Old Horde, Gul'dan and the Shadow Council cared little for and ignored the Shadowmoon's warnings. They conducted a ritual to call on the Dark Star in their war against the draenei and channeled it at Karabor, the draenei holy temple in Shadowmoon Valley. A pillar of Void energy ripped through the heavens and slammed down on Karabor, driving many draenei defenders to madness while many others died instantly. Velen called on his powers to keep the Void at bay and rally the survivors to Karabor's harbor, but the Dark Star had forever darkened Karabor, and it became known as the Black Temple and was taken by the orcs. The option for the Horde to harness the Dark Star was no longer available after this. What happened to K'ara after this, including whether it survived the destruction of Draenor in some fashion, is unknown.

Trivia

 * K'ara and Xe'ra are the only naaru to be referred to with feminine pronouns, with Velen repeatedly calling K'ara a "she" in The Prophet's Final Message. However, while Velen's audio uses "she" the text in his speech bubbles uses the gender-neutral "it." Chronicle also refers to K'ara as "it."
 * The word "Kara" literally means "Dark" in Turkish.

Speculation

 * A shard of K'ara may have been the crystal that became the Ashbringer.
 * K'ara may be where Karabor got its name, considering the closeness with the nearby K'arani Terrace.