The Orb of the Sin’dorei disguises the user as a Blood Elf.
The transformation lasts for a total of 5 minutes and it has a 30 minute cooldown.
All my toons are Blood Elf so I grabbed the pic above from Wowhead to show a transformation. If your a Blood Elf the Orb of the Sin’dorei will do nothing.
The Orb of the Sin’dorei drops from the following bosses in the dungeon Magisters’ Terrace:
The Orb of the Sin’dorei has a very low drop rate and is bind on picked up so you may have to do some farming to add this to your collection