At this phase, there is one mob for each group. Make sure you have a tank in each group. Players in each group target their tank, the mob spawns on the tank. (It may be that the mob spawns on the first player in the group, but since we always place our tanks first in their group, it's hard to tell for sure). Once again, you are on a time limit, if any of the four mobs fails to die in time, the encounter resets.
Phase three is the hard phase. The trick to making this phase work is to save all of your big DPS abilities for this. Yes, there is a time limit on the first two that sort of makes you want to blow your big stuff, but you have to resist that urge and find the balance point where you get the first two phases dead, while not blowing your good stuff.
When phase three spawns, each player is assigned a 'color' . . . blue or yellow. Your entire SCREEN turns this color (blue is sort of purple to me (Wizard Snow Filled Steps), but yellow is the piss yellow you see often (Conjuror Cat's Eye)). One of the mobs spawns on the first player in Group 1, the other spawns on the first player in Group 3. You want these mobs separated, so position those players accordingly.
As soon as you have a tank on each mob, BURN LIKE HELL. The beginning of the fight is your best chance to get the maximum damage done.
Here's the trick. If you damage the wrong mob (yellow player damages blue, blue player damages yellow) it lets the mobs cast a MASSIVE power drain. You MIGHT recover from one of these, or even two if they are spread out in time, but if you have people who suck, they are going to wipe your raid.
It gets better. After some amount of time, maybe 60-90 seconds, the mobs start swapping color. So the blue mob becomes yellow, the yellow mob becomes blue. Further switches can in fact see BOTH MOBS TURN ONE COLOR! This is another reason you'll need four tanks, one in each group. This color switch is preceded by a red text message to the entire raid maybe 5 seconds before it happens. Existing DoT spells *DO NOT* need to be cancelled on a color switch.
So, don't damage the wrong mob, pay VERY careful attention to color switch and make sure you never attack the wrong color. Keep in mind that you have to *read* the color of the mob from it's name. With the screen turned to whatever color you are assigned, you cannot actually tell by looking what color the mob is, you have to read it's name to be sure you are hitting the right color.
Stage three is really simple if you have tanks who know what they are doing. Two tanks have a target macro for "/target A Yellow" and the other two have '/target A Blue". ALL group members target only their tank. When the red swap message pops, tanks hit f1 to target themselves and then as soon as the swap happens, spam the target macro and go to town.
I am curious though if this can be done with two tanks. Going to try it soon.
We use a warning when color switches are occuring and tell all our players to clear their target and turn off auto attack until they are sure of their target.
We pull the two mobs fairly far apart and then have all our players right on top of them so that even if they are force targeted, they won't be in range to hit the wrong mob. It's very possible that the force target has a limited range on it and that you won't get it at all if the mobs are far enough apart.
The swaps seem to come faster as the fight proceeds. It seems very important to do the initial burn on the third round very, very fast.
Mages and priests should not be using secondary and/or ranged items with ranged auto attack on them. Target locks can cause your ranged auto attack to damage the wrong mob.
Something thats kind of important and I dont think is mentioned is that the golems for 3rd stage do force taunts so its important to keep your ranged in a position where they wont accidentally be taunted by and be in range of the wrong golem.