Saa'ra

Saa'ra is a naaru located in the Sanctuary of the Light in Netherlight Temple. Saa'ra was once transformed into the Void god Saraka the Lighteater before being turned back into a naaru and is the only known example of the void creature transformation being undone, with the exception of the alternate purifying the naaru  in.

Legion
Saa'ra is purified by the Conclave.

Before the Storm
Calia Menethil would speak of her nightmares with Saa'ra, who would usually offer her comfort and insight. On one such occasion, Saa'ra told Calia that the nightmares will stop once she was ready for them to stop and that there are things she must do and become before that peace would be granted unto her. However, Saa'ra also warned that some of her trials may involve pain and blood. Though Calia admitted it didn't make her feel any better, Saa'ra told her it might once she understood that even painful developments may become hidden gifts and to trust in the purpose of her destiny. Eventually, Saa'ra's insights and warmth would ease Calia's apprehension and comfort her. After their discussion, Saa'ra told Calia to sleep in peace, prompting a calmed Calia to go back to bed.

Following the tragic end of the Gathering, Saa'ra watched over the non-decomposing corpse of Calia in its chamber and told Alonsus Faol to wait for Anduin Wrynn's arrival. Once Anduin arrived, the naaru stated that Calia would become free from pain and nightmares and that Anduin and Alonsus would bring her back as the Light and she herself would have her be. With Saa'ra's guidance, the two priests raised Calia back to life with the power of the Light, but as an undead.

Objective of

 * Halls of Valor: The Light Within

Speculation
One of N'Zoth's whispers during the Uu'nat encounter is whisper Windrunner: Three Sisters implies that the Void regards Death as "the true enemy". As such, N'Zoth's whisper may refer to Saa'ra's resurrection of Calia as being part of an alliance between the Light and Death.