Voice of the Light
The Voice of the Light (or the Light-That-Needed-Saving) is an entity that is calling to Aramar Thorne in his dreams. It is connected to a compass that was previously in the possession of Greydon Thorne and is currently in the care of his son, Aramar. Malus, having already had a certain history with the compass, and the Hidden, are looking for it as well. It is pointing to crystal shards across the world.
Thalyss Greyoak gave the following description for the compass needle: "It is a shard of pure starlight from heavens, imbued with the celestial spark. It means the crystal needle is not of this world."
The Voice first called Aram while aboard the Wavestrider, revealing that it needs to be saved. While in Feralas, it appeared in his dreams several times, but Aram felt that he was always turning away from the Voice. When it last appeared, it did not do so in his dreams, but rather it appeared in a vision when he touched the glowing compass' sliver of crystal, after the object had forced itself to the ground, discovering a new crystal shard and creating a small crater near the border between Feralas and Thousand Needles.
Upon the end of the vision, he felt that this time, he did not turn away from the Light. Makasa, one from his group, awoke Aram and he told them about the Voice. They decided to continue their journey to Gadgetzan and resolve its mystery.
Upon finding and joining the second shard with the first one, the Voice told Aram that there are seven shards that need to be joined into one. The crystals are a part of the sword called the Diamond Blade which was previously in possession of Malus, but he had betrayed someone and forfeit the claim.
The Voice of the Light may actually be a naaru as the Wavestrider's figurehead resembles one and was carved by Anselm Yewtree on Greydon's extremely precise specifications. The crystal shards and the compass needle may be of a naaru origin as well.