nailbat.us

I did this fight a handful of times and observed a simple way to see where to stand.
What i did was to always look towards the next safe zone (this means repositioning the camera pretty often). When the ground erupts, assuming you're standing in a safe zone, you'll see a wall of green coming out of the cracks. The safe zone that you're currently standing in is very well defined at that point. The key to getting to the next safe zone is to go and stand where that 'wall' was, and not to cross it. In other words, the safe zones overlap! It is not necessary to run completely out of zone 1 to be in zone 2.
I experimented using this method on my last run through it and i was fine. Previously I'd sometimes get hit because I ran too.

Another neat side effect of this observation is that you hardly have to move between 3->4->3 and 2->1->2. basically, if you stand on the border between 3 and 4 and you'll be safe from 3 and 4, and you can stand on the border of 2 and 1 to be safe from both. This has allowed me to fire off some random shots (non-instant). Probably only enough for a half second cast, and I would not recommend attempting this unless you are very confortable with the dance.

You mean Heigan and the safety dance. ^_~

But yes, camera positioning is huge for this fight. Second only to positioning yourself. One thing I've noticed myself is that on phase 1, I end up having my view going from the platform looking outwards of the room, and on phase 2 I'm watching the platform while running. That may just be to also keep an eye on where Heigan is, since the tank drags him along far from the ranged peeps.

Definitely, watching the eruptions from a view where you can see what cracks they come from helps identify where the zones are, and then makes crossing those borders very easy.

If I wanted to mislead you, I would say that the zones are defined by the diagonals and the center line of the platform. Truth is they are close to that, but not quite. The zones are also somewhat asymmetric- I get the sense that zone 3 is a tad wider than 2. All of which makes the timing of the dance tricky- it means it takes longer to run across 3 than across 2. But then it just all comes back to timing, paying attention, and sadly, latency.

I died to disease yesterday, where is a good place to stand for melee in transition from phases?

yup to the title... i don't know these bosses yet >.<

As far as the prefered dying place? probably zone 1. since that's where the transition from phase 1 to 2 and back to 1 always occur. Though honestly as far as B.rez is concerned, this fight is really difficult. Whatever you do, don't accept a b.rez when the zone you're standing in is about to explode.