The best way to do this achievement is to have sufficient DPS that you only have 2 times you have to interrupt. Bring a warlock. The warlock uses their felhunter with its interrupt autocast disabled. A DPSer interrupts the first cast (as close to the end of the cast as possible, you want him to spend like 7 seconds casting and then get interrupted right at the end, that is free DPS time). After the first interrupt is done, the warlock turns on the pet's automatic interrupt. This effectively removes reaction time and latency from the equation since the interrupt is autocast. The felhunter interrupts the second, the boss falls over, you get your achievement.
This fight is short enough that you shouldn't require any healing. Your healer should have a DPS spec. Generally bring a shaman healer with an enchancement or elemental spec because they can even leave an earthshield on the tank before they respec to their DPS spec (though I'm sure they will fix that eventually to match other buffs that fall off on respecing). They also provide heroism which makes it easier to have a 2 cast fight.
If you require more than two interrupts, bring another warlock. Problem solved.
The entire problem with this achievement is it is fundamentally luck based when his cast time drops to the point where it is faster than latency + human reaction time. Because of that, you have to be interrupting before you see the cast towards the end of the fight because your reaction time is too long. You remove the reaction time aspect of the achievement completely from the equation by using an autocast interrupt.
Last edited by Quinafoi; 02-16-2010 at 08:45 AM.
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