It's about time we looked at getting more HM boss fights done. In my opinion the poison boss is probably the the one we should look at first. We have already killed him several times in T2 normal mode and know the basic mechanics of the fight. However HM requires a lot more concentration and timing/organisation. I'm going to write a few notes for a strategy down now to outline some of the requirements to get HM done.
What do we actually need to do for HM? It sounds fairly simple but can cause a lot of problems with a few of the other scripts involved in this boss fight, but basically all we need to do is make sure at least one person is stood on the platforms at all times. As I'm sure all of us know by now that there are four platforms in the boss room and each of us has to use the platform several times during the fight to reset a DoT that tiers up the longer you stand in the water. Not forgetting that if two or more people stand on the platform for more than a few seconds then it will collapse and HM will fail.
Another mechanic the boss has is the 'Catch' script. He will throw a boulder at a member of the raid that will knock back that person and anyone around him. This causes problems if the person that gets the boulder thrown at them is standing next to somebody on a platform, knocking them both back and failing HM. To get around this we assign a member of the raid (preferably Captain) to be the 'boulder catcher'. A lesser known fact about the boulder catch script is that if all members of the raid are closer than 25 meters (not confirmed distance) except one person i.e. the 'boulder catcher' then he will always target that person at more than 25 meters away. This allows us to controls this mechanic without having to worry to much about other people getting boulders thrown at them.
Another thing that can cause problems is the Root mobs. These pop up at people feet and root anyone around them, including the member it appeared on. This can cause problems as people are trying to reset their Dots. If a person that needs to reset their DoT jumps onto the platform right by the person already on it then they both get rooted, the platform then collapses and HM fails. To get around this positioning and ranged DPS need to be spot on. By positioning I mean the person that wants to reset their DoT needs to stay away from the person already on the platform (usually healer or light armour). Simply they need to go to the back of the platform, tell the person already on the platform they are ready (making sure they scream out if they get rooted), jump onto it, the healer then jumps off the front of the platform and move to the boss, the DoT resets, healer runs back and jumps onto the front, person with no DoT jumps off the side. Any root during this phase can be very hard to deal with and ranged DPS need to take care of it fast.
Lastly to make the DoT resets as smooth as possible we need to stick to a strict order of who resets DoT's and when. It can be quite easily managed by assigning each platform a 'place holder' (I'll call this PH from now on) and the other two members of that platform '1' and '2'. Remember there are four platforms in total and 12 member in the raid, therefore each platform gets three people, the PH, number 1 and number 2. All PH start the fight on the platform, as close to the corner nearest the boss as possible. All other members stay closer than 25 meters except the boulder catcher. The boss activates and we begin the fight as normal, de buffs, DPS, ect. Remembering to kill roots as they spawn. Fairly early into the fight that boss will call for his add Nemual (or something like that). As usual this is killed as soon as possible. After his death all number 1 people will reset their DoT's by using the described method in the paragraph above. As soon as this is done we go back to DPS'ing the boss. After some time he will call Nemual a second time, and again this is DPS'ed down as normal. After his death all number 2 people will reset their DoT. All we have to do then is rinse and repeat.
I know this is very long winded but people need to understand every part of the fight. It's a lot to take in but when we try just concentrate on what your doing and remember your number and platform.