1) Take the teleport in the violet citadel to the purple parlor
2) Mount up
http://img360.imageshack.us/img360/1926/ally1dq1.jpg
3) Fly down to the alliance area
http://img184.imageshack.us/img184/3638/ally2ce2.jpg
4) Fly through the door and land in the middle of the staircase and you won't be teleported out
http://img339.imageshack.us/img339/5378/ally3kz9.jpg
5) Walk onto the edge of the stairs and you can follow the ledge around
6) The battlemaster spawns under the marked arrow and can be killed. You can walk up to about the area marked on the ground before you get teleported out
http://img377.imageshack.us/img377/4969/ally4sb1.jpg
by poppy