As title says, skyfury totem stacks and transfers to pve dmg if you manage to get it down. You can only place it if you engage in pvp (its a ele sham pvp talent), but if you say windshear a horde right before pulling a world boss, the buff lets you do some insane dmg. I've crit for 2mil (earthshock) and I have pretty horrible gear around 810 ilvl.

http://www.wowhead.com/spell=204330/skyfury-totem

Summons a Fire Totem with 5 health at the feet of the caster for 15 sec that increases the critical effect of damage and healing spells of all nearby allies within 40 yards by 30% for 15 sec.

You burst at over 1 million dps with ascendance. I love it :P