This was one of the more challenging things I’ve done in awhile, and what fun! After quite a few failed attempts – which usually had me frantically mashing buttons during the final seconds of the 10th wave – I finally managed to down the last Sha with barely a moment to spare. My ilvl 601 gear consisted of a few decent PvP items, a couple dungeon blues, and some quest gear. I used my standard BM build along with a cheap haste potion to get the job done.
After about 8 or 9 attempts that left me feeling a little inadequate, it finally occurred to me that the buffs that spawn during the encounter did not have to be used immediately.
/facepalm
If you’ve yet to attempt or complete this achievement, I’ll say it again…