Arcane Anomaly's are found in the Menagerie part of Karazhan.
This was something we bumped into by accident from a bad pull, anywho, a hunter can take the anomaly out in just a few steps leaving you to only deal with the syphoners.
--Have a hunter shoot it and immediately feign death, this will remove its mana shield momentarily.
--As soon as aggro is reset (should only take a second or two) have the hunter pop up and blast it with any shot that will cause more than 998 damage.
The anomaly dies since it has very little health and no mana shield to absorb damage leaving only the syphoners to be dealt with.
Should save your raid 30-40 minutes and a wipe or two
