Since I beat this the 1st time I have had this on farm.
1 reason for that, is having 2 healers. SK,BRD,SHM,CLR,ZER,ROG. It's far easier with 2 healers.
I just burn from the off, Aary down to 50-60, run to tunnel, hammer Grolik till he despawns, run and stand at the edge of the brown area waiting for grolly to reappear. Soon as he pops you can run into the brown area and tag him, 10% health normally takes about 3 or 4 seconds and he goes again.
Soon as you see emote of the orbs appearing in the corridor, go and tag them and get agro, run back to brown jump on grolik.
He goes down another 10%, when he drops down look for next brown patch and run to edge, beat on orbs a bit to keep agro, they eventually clear off.
Guardian golem normally spawns when grolik around 10%, tag him, get back on grolly, beat on guardian whilst grolly underground, you should get him to 50% ish,
Finish off grolly, jump on dragon beat dragon down to 20% ish, he flys off, kill off guardian, do TA's then open chest.
Only time ive screwed this up since farming it, is when some sort of stone covering appeared over the group and i couldnt figure how to get out. It reset, and I just did it again.
Dont need to use Glyphs or really burn, Grolik is a wimp, and I dont bother with the Auras,