In the Aberrus raid, several Void references can be found, including in both the Neltharion fight and the final boss fight against Sarkareth! Patch 10.1 is full of Void and Old God hints so far, such as the N'Zoth fish that's been discovered, and the ever-present Shadowflame. The Aberrus raid is no different, where several Void references can be found throughout:
A series ofvoid-themed icons with the name «cosmicvoid» have been added. Apart from various Corruption and Shadow-themed abilities, the Echo of Neltharion encounter shorthand is also ‘faceless one’ in placeholder items, such as with the 10.1 Raid — Black Dragon Labs — Boss 08 — Faceless One — Weapon — Shield. Faceless ones, or N'arqi, are an Old God race who often serve as commanders. Scalecommander Sarkareth, leader of the Sundered Flame and final boss of Aberrus, has several Void-themed abilities. Sarkareth also drops the Beacon to the Beyond trinket, which has an interesting on-use effect: Briefly open a pair of gates to the Void to redirect the orbit of An'shuul, the Cosmic Wanderer through your target, dealing 357238 Cosmic damage split between all nearby enemies. What Does It Mean?Aberrus is Neltharion's laboratory, where he conducted many experiments in secret. It was within Aberrus where Neltharion created the Dracthyr. In the Secrets of the Reach cinematic, the Primalist Incarnates discuss their intention to find a way into Aberrus, specifically to harness the molten fire that empowers it. Sarkareth overhears, and determines to enter the laboratory himself, in order to reclaim what remains of Neltharion's legacy for himself.
Iridikron: The laboratory itself is of no consequence. But the molten fire that empowers it… that we can use. Sarkareth: Read more on wowhead.com