its called roulette

[Ashkendor]

All hail 2nd boss in Fractal :P. One trick I don't see used nearly as much as it should be is interrupting his charge move (grunt something). You can activate the add tank and he'll reset his rotation, making the entire fight simple and fast .

You can't do it if the party is terribly low DPS, or you risk not being able to interrupt his room-wide AoE. :/