I’ll do this in a boss by boss rundown with any notable trash to watch out for as a healer (there is always that one nasty trash mob that will take you completely by surprise). Most of my perspective is as a druid healer, but if there is anything notable that might be more difficult or easier for another healing class I’ll note it in my discussion.
Hopefully your group cleared the first 3 groups between the tunnel ramp and the boss’ platform, otherwise you’ll get overwhelmed. There are basically two different abilities to this fight. The first, is the Quake ability, stay close to the tank (but not too close), use an aoe heal, and move out of the quake ground effect (about 5 yards). As always, make sure the tank stays topped off. The second ability is the Chains of Woe. This ability summons chains binding the party until the chains are destroyed. If the tank isn’t at a safe health level, this is a good time to heal them up. Keep the chains or the boss targeted if you can so that you know exactly when you need to run away from the boss (about 10-15 yards).
He summons adds during the Quake ability so it’s important for the healer to be in close to the tank for them to be picked up. Also, on heroic mode there is just enough extra damage thrown around that the Chanis of Woe are your opportunity to get everyone’s health levels back to safe levels so you probably won’t be helping out with the dps there.
There are a couple of trash mobs leading up to this next boss that have a nasty ability that does about 30,000+ (i.e., 60% of health) damage (Gravity Strike) so be on your toes.
Corla, Herald of Twilight
Two people can alternate standing in one of the beams until you’ve stacked up 70-80 stacks. When that happends, run out of it. Run into the beam again when the debuff has dissapeared. Rinse and repeat. If you or the Twilight Zealot get 100 stacks, you get MCed or the Zealot Evolves into a beast which can easily whipe the party. The Evolved Zealots have that nasty Gravity Strike ability that you saw on the trash. Secondly, there will be a fear that can be cleansed and will keep the rest of your party performing their beam dance.
There are 3 adds now so you’ll definitely be one of the people standing in a beam. Hopefully, by this time you know how to set a focus to watch both the Twilight Zealot’s stacks and your own. Do a beam dance while healing the tank. Fortunately, Corla doesn’t pound the tank so just watch your mana because this is more of a concentration and endurance fight.
This boss is the real skill check for your tank, so do what you can to make it easier on them. The trick to this fight is to stack the debuff Superheated Quicksilver Armor slowly by moving the boss in and out of the flame. The flame pillar doesn’t cause any line of sight issues so standing on the other side of the pillar from the boss works very well. It will also keep you out from in front of his cleave effect.
My guild found that clearing the edges of the room before the boss made it easier to deal with adds away from the tank. Also, watch line of sight on your dps as they will likely be pulling the adds outside of the outer ring. The AoE damage from 8-10 stacks is managable even with heroic starter gear, so don’t panic if the tank gets a higher stack than intended from a single trip through the flame.
I love the 101 dalamations reference for this boss. In regular each of the puppies can be pulled separately, just stay out of their Magma Spit (i.e., drool). Beauty is pretty straight-forward but she has a periodic fear that will often put you out of range of the tank, so be ready to run back towards your tank.
The puppies are pulled with the boss in heroic, so there may be a little more damage incoming to the tank. However, if you have good crowd control for the puppies your biggest concern will be the timing of the fears by Beauty.
Beauty’s Favorite Bone – A nice offhand that is worth picking up just incase you get a good mace to drop.
Beauty’s Silken Ribbon – Priest waist
Kibble – A good second ring if you have made friends with Therazane
Ascendant Lord Obsidius
This boss has lots of nice gear for the healers, so you’ll really feel rewarded when you get this one down. Lord Obsidius has 2 adds (Shadow of Obsidius), who take no damage and reduce healing done on their target if Obsidius is close to them. With good CC or kiting skills on the part of the dps you shouldn’t have any problems with the debuff, but keep an eye on range for healing. Obsidius will periodically “posses” one of his Shadows, switching places and resetting aggro with it, so watch where you’re standing.
Easiest of the bosses if you have good crowd control in your group. Otherwise that debuff will stack up quickly on the “off-tanking” dps.
Kyrstel Mantle – Priest Shoulders
Willowy Crown – Druid Hat
Clutches of Dying Light – Paladin Gloves
Crepuscular Shield – Paladin healing shield upgrade!
Witching Hourglass – Great Trinket for any healer