The Void Focus is a crafting station where you can craft the new 8.3 recipes. (It works exactly the same as the Abyssal Focus worked in patch 8.2.). At first, you can only craft the ilvl440 gear with it. You will need to upgrade the Void Focus to its max level in order to craft the highest ilvl gear (ilvl 455/470 gear). It has two upgrades "Empowered Void Focus" and "Dreadful Void Focus".
Upgrading the Void Focus is permanent. You don't have to upgrade it for each item, you can craft as many as you want once upgraded.
How to unlock the Void Focus
1. You have to loot a Recipe: Void Focus from N'Zoth assaults or Lesser Visions. It's a random drop from Faceless, K'thir, Aqir, and Cultists mobs that worship N'Zoth.
2. Use the recipe, then farm the same mobs for 10 Void Focus Splinter. (These same mobs drop the rank 1 for the new raid recipes, so you should keep farming them until you get the recipes.)
4. Go to the Chamber of Heart and turn in the quest at Wrathion which unlocks the Void Focus. Now you can craft ilvl 440 gear.
Upgrading the Void Focus
You will automatically get the first upgrade quest once you finish the first Void Focus quest.
The second upgrade is called Dreadful Void Focus, it will let you craft ilvl470 gear. You have to complete the Dream Catcher quest to get this upgrade. You will need to collect 200 Shred of Insanity to complete the quest.
How to get Shred of Insanity
You can get Shred of Insanity from bosses in Ny'alotha, the new World Bosses, by winning Battlegrounds and Arenas, or from Honorable Kills.
- World boss and Normal raid boss - 1 Shred of Insanity
- Heroic raid boss - 10 Shred of Insanity
- Mythic raid boss - 20 Shred of Insanity
- Arenas and Battlegrounds have a chance to reward Shred of Insanity after a win.
- World PvP - Low chance from an Honorable Kill.
Where is the Void Focus
The Void Focus is located behind Wrathion in the Chamber of Heart. (once you complete the quest)
I included this part just in case you completed the Void Focus quest without realizing what it was.