That being said, she's by no means a cakewalk even then. I tackled her using a turtle (rotating Cower/Shell Shield as needed; had to pop Last Stand once), 387 PvE gear + 397 PvP bow (LFR 2-set for the focus bonus from Cobra), & BM PvP spec & glyphs (so mend pet was Super Effective!). My BM PvP spec has the extra stamina talents in Survival, which translates to more pet HP which translates to bigger Mends. My turtle, Brimstone, generally has around 140k health.
Tactics Brimstone hovered between 80% and 50% hp for most of the fight. I kept Mend up 100% of the time--Xariona's melee still hit for ~40k quite a bit. My turtle sat in the anti-magic-pool, although with pet anti-AoE he probably wouldn't take much damage from Fissures anyway. Leave the pet in the anti-magic pool, facing AWAY from you (I pulled her myself and then pet-taunted (& hit MD) once she'd passed my pet, so she turned her tail to me), and move whenever she casts Twilight Fissure on you. You're a hunter and you're alone, and hopefully at range, and she's facing away from you, which essentially nullifies every one of her other abilities. If you tackle her with her buff up, you'll need to get into the pool she's facing every time she does her big AoE, or maybe Deterrance? Not sure how often she casts that, so whether it's counterable or it means you'll just die, I don't know
This fight took 14 minutes and 46 seconds with 14470 DPS (don't mock me, it was a turtle + PvP spec! 
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