Succor before, Indom after just in case, FFXIV and you're money.
|Title||Succor before, Indom after just in case, FFXIV and you're money.||
|Description||If your party is getting exploded right after the adds, it's a DPS problem, not a healing problem. His big AoE is scaled based on how many of the Holy Flames are still alive. If you're too slow in killing the Flames, it's an instagib no matter how much shielding you do. If your dps is on point, it hits for ~40% of max HP completely unshielded.
Succor before, Indom after just in case, and you're money. There's not really anything else worth using Idom for. You shouldn't need Emergency/Deploy or anything.
Also, as soon as Charibert jumps at about 50%, there is zero damage coming for the next 20 seconds or so, aside from the easily dodge line attacks from the Knights.
Make sure you're in Cleric and going HAM on the Flames right when they spawn.
In a competent group, that fight is easy to heal, because the only attack you can't dodge is Altar Pyre and auto-attacks. Alas, it's one of those fights that can be a complete nightmare with a less-awesome group, because there's a ton of stupid to stand in.
Right after that phase, the boss makes you think you want to aoe heal but you don't. There is a big tank buster coming out next and aoe healing will kill the tank. The tank should mitigate and you should focus heal the tank at the start of the second half. Try using the AoE regen on Eos+Succor at the end of the add phase and that should cover you while you focus on Adloing and keeping the tank up.
That's likely because the frequency of mechanics increases drastically after the holy fire.
You can usually just use succor. If there is already a shield on everyone in the party, and everyone still has 2-3k hp to go before full health, then Emergency Tactics + Succor does help. But, again, if nobody has a shield, Succor should do the job. I've found success using Indom too, because it's essentially a free (and powerful!) aoe heal. Again, you can use it if people are 2-3k below maximum health.
You can use Eos' Rouse > Whispering Dawn combo to help push more aoe healing to your party, as well.
Otherwise, you should probably be spending FFXIV Power leveling(http://www.ff14gilhub.com/ffxiv-powerleveling) most of your GCDs topping off the tank with physick.
Like the other reply mentioned, try to have a book that is at least level 56; it helps drastically in clearing the fight. Leftside gear should probably be at least level 52 (i120), but any upgrades to that really do help.
It's also possible that your party just doesn't know the fight's mechanics/dodging very well, or is taking unnecessary damage. :P
It's assumed they either A) travel or B) where at each location independently depending on where you are in the story.
You'll see a few "inconsistencies" that depend on what part of the quest you're in, where you'll see one NPC elsewehere who is supposed to be dead in the main story but alive in a job quest, or things like that. It depends sometimes on patch cycles. A quest may have been introduced in 2.1 in one area that got "destroyed" in .2, but you're supposed to ignore that if oyu go back to get the 2.1 quest.