Staff Of Void Quest

This is just a general rough guide.

Go down in stables and kill clockwork homunculus for a heavy silver key.
That key unlocks a door 2s of Vymm (portable) which is a room with a runed tower key.
The tower key unlocks the arcanist tower door (track void), an east locked exit.
Go up in tower to Empty Servitor.
Kill the empty servitor (level 70).
Servitor spawns an aggie 'a silent slice of void' (also level 70).
Silent slice of void drops invis void essence when it dies.
Acolytes are east.
Give void essence to void acolyte and you'll get Staff Of Void.