we've been having the same problem, the solution is very easy. let ur tank make a macro with a target and a taunt he can spam, this doesn't always work since the damage is so quick, but avoiding is really easy: use fade, threat reduction, feign death... or just run out and get out of melee range, that's the easiest. have you're tnak count down when the head is going up again and at 3, run out and 2 secs after it's up, tank should have threat and u can get back to nuking