The source of the staff nightmare fell in the Naxsamas tectonic zone Groblous, the following is how to go
Methods/Steps
1
We teleport from Stormwind to Dalaran (Crystal Forest), and the horde can teleport to Og
2
Then fly over the Late Winter Fortress in the Keel Wilderness
3
The replica entrance is at the bottom of the Air Naxxamas, marked in red circle
4
Enter the copy and drive to four zones. The fifth section is accessed via a teleport orb on the second floor
5
Zone 4 is the construction zone with four bosses in the upper left corner
6
The first is Patchwick
7
The second Grobrous
8
In addition, all the weapons in the first four zones from the construction zone to the third Geras falling on Naxsamas can also be brushed