you can almost solo this fight with Hyjal wisp. Use two manasfiend to finish them off once Wisp dies. Just open with arcane, then wish and evanescence after howl, make sure you have evanescence up on the first turn once the second pet comes in to dodge Curse of doom.
Yup. Wisp is definitely king of this fight. Beat first beat, baited second pet into using its suicide move during an evanesence, and got third pet low enough one surge from a manafiend finished it off no damage taken.
I decided to use Absorb instead of Ooze Touch and Oily Slimeling took out first 2. Used Viscidus Globule 1,1,2 as per Anne's comment to take out the third and they duoed the fight. Didn't need my final pet
I was successful with Oily Slimeling (1,1,2), Viscidus Globule (1,1,2) and Blood Boil (2,1,1). Followed the same priority as above as well as tips from Anne above. For Blood Boil, used Plagued Blood in place of Acidic Goo and Corrosion and used Drain Blood once for a nice heal. Good luck!