Each time you go through Phase 1 you will want to keep an eye on Earsplitting Shriek. It places a 12-second DoT on the whole raid. Keep an eye on Line of Sight since a lot of mechanics require you to hide behind pillars and think about where you place your Healing Rain. Overall very low healing requirement so don’t overthink the fight too much and just deal with the mechanics.
Make sure your UI allows you to heal NPCs that spawn during the encounter, as one of the mechanics (two on mythic) will spawn friendly NPCs that require healing before they reach the boss.
Sun King's Salvation
Make sure to equip on use trinkets like IQD to pump boss healing inside your ascendance window. Ask for innervate/PI.
Raid healing doesn't matter as much, just heal the boss. Inside Ascendance spam healing surges for more healing throughput.
Fairly straight forward patchwerk fight. For the encounter, make sure you can see Gluttonous Miasma on your raid frames, as those are players you cannot heal, they have to use the mechanic themselves to leech from players around them.
Generally, just play as usual and make sure to keep an eye on stacks. Since the longer a person soaks the more damage they will do. Healing Rain is very good here since you’re stacking most of the fight, so make sure it’s always active.
Lady Inerva Darkvein
Using the Graceful Spirit talent is nice for this fight.
Healing wise, there is nothing special to the encounter. There are some mechanics that require movement, so make sure you keep track of your boss-mods for the timer. If there’s an ability you need to move for coming up in a few seconds, don’t place a Healing Rain until the movement is over as it won’t be effective.
The Council of Blood
This fight is a patchwerk encounter, with the damage intake on this fight being spiky and slow. When the boss slams into the pillar, you can place a Healing Rain on top of him, since this is where melee is going to be. Then try to do as much damage as possible with Flame Shock and Lava Burst as there’s no major rush to heal players up.
Position yourself so your Wellspring can hit as many targets as possible.
If you want to pad, you can cast a Wellspring on pull.
Stone Legion Generals
The encounter has a lot of abilities that will force you to move, try to optimise your ability timings to allow the use of instant casts or Spiritwalker’s Grace when you are being forced to move. For phase one, Ravage will force you to move to a different part of the room. For phase two, Hand of Destruction will cause movement. For phase three, Ravage will once again force you to move.