Near the end of thaumcraft wands are split into two groups: staffs and specters. specters can not have a wand focus so they are only for storing vis and crafting, they also have 3 wand caps instead of 2. Staffs are larger than specters and wands so they can store much more vis, however they can not fit in a workbench so they cannot be used for crafting and are slightly harder to charge. Whenever you research something in thaumcraft that is forbidden knowledge you will gain warp, warp can cause all kinds of negative things so most people try to avoid it, When you have gained a lot of warp a new tab will appear in the thauminomicon: "Eldritch empiphany" It will explain that your player has gone insane and is now doing all kinds of dangerous dark magic. One of the researches in this tab is the primal focus, On it self it is useless but when you scan it you will get a research note for the staff core of the primal. It is impossible to make a void aspectet primal staff or a thaumium aspectet primal staff because it requires more vis than any wand in vanilla thaumcraft can hold, however if you make a full set of void armor(3 pieces) and a void aspected silverwood specter it will decrease the vis just enough to make a thaumium aspected wand. How did I make a void aspected staff? I used my moderator powers to put a 4th piece of void robes on (the part that is supposed to go on your leggs was also on my feet). Some items from the Eldritch tab are not in NEI.