I got the axe the other day and I would say a RDM around 65 could solo it with some time. I helped a couple of my LS mates kill it (and they got me the axe) the other day and the way our Taru 75 RDM did it was to just Kite it in circles around the cave there with Gravity on it.
We would run ahead of it, turn and shoot, cast, whatever we could do to hurt it. As a 54 RNG I could hit it decently (without food at all) but my damage was almost non existant...
I was hitting for about 20-30 points of damage every shot and I landed a Sidewinder for a massive 102 damage! Our RDM was the damage dealer because he seems to be VERY weak to Ice/Thunder because Blizzard III was landing for about 700 dmg each cast and took a significant chunk out of his life bar each cast.