Its on the 3rd floor as you enter 3rd floor look for a fake wall on the
right (it has some little holes in it, You could also take the quick route
and drop down well.
As for getting it at 21 that wont be a problem but you really need a
group here because the room constantly spawns and you must kill all as it
does. Grouping here is usaually not a problem the robe and dagger spawn in
the two little alcoves on the left and straight as you enter fake wall but in
the right alcove is the famous BBC spawn. Good news is the robe and dagger
spawn more frequent than the shadowknight. I got my goss robe and dagger off
same necro theur.

Zakrell Lu'Dan