there is a trick to doing this with just 1 tank, you need a 2nd person who has a taunt ability tho. the pattern is always the same -- he throws rock shards on someone, a few seconds later he leaps on someone, a few seconds later he throws rock shards on someone, and then 1-6 seconds later he will grab the current tank.

So you could have an OT DPSing and taunt right after the 2nd rock shard, and he will always get grabbed (he will only "tank" the boss for 1-5 seconds). Of course this person still needs heals and to reposition after getting thrown out of the hand.

I once tried 5 boxing it (pally+4 shamans), the trash was super easy but I couldn't do the boss since I didn't have a 2nd person to grab so he'd just kill 1 person at a time after each grab. I imagine if you could bring a friend who is either a real OT or who can taunt and has good gear you can probably do it.

I also seriously doubt your ele shamans do 7k dps sustained. Lust is only 35 seconds, the boss fight is longer than that