While we've talked about the strengths of the holy paladin recently, and why they're so suited to tank healing, the fact is that not every fight revolves around two tanks getting smashed. In fact, there are actually more 'raid damage' fights than there are 'tank damage' fights in ICC, and so learning to cope with massive incoming raid damage becomes an important part of any paladin's training. While we will typically have the support of an AoE healer of some sort, we can't rely on them to do all of the work. Even though our primary heals are all single-target, we have a few tricks up our sleeves.
Judgement of Light
While this one may sound simple, the fact is that Judgement of Light can easily account for 10-15% of your healing done on any given fight. On a recent Blood-Queen Lana'thel parse, JoL amounted for 25% of my overall healing, and also had a lower overhealing percentage than any of my other heals. Some paladin should always be using JoL, and since holy paladins have a special flavor of JoL due to its interaction with Divinity, it should be us. If at all possible, keep Judgement of Light up on as many targets as you can. On a fight like Twin Val'kyr, you can easily double its value by maintaining the debuff on both of the Twins instead of just one. The tier 9 2-piece bonus can help you maintain solid JoL uptime.
Many AoE damage auras that we encounter are magic-based, and belong to a particular elemental group. For example, the Twin Val'kyr auras do Fire and Shadow damage, based on which mob we're talking about. Using the proper aura can reduce incoming damage by as much as 20-40%, which is huge in terms of additional survivability and a lower amount of damage to heal. Aura Mastery is especially useful, as it can significantly reduce incoming elemental damage. I used Frost Resistance Aura + Aura Mastery as a powerful combo on Hodir hard mode, which allowed me to essentially negate his AoE Frozen Blows attack.
Holy/prot paladins will also have access to Divine Sacrifice, which will allow you to redirect a whole load of additional damage to yourself. If you pick up Divine Guardian, you get an additional 20% reduced damage to everyone in your raid, which can be handy if you know there's a large amount of damage incoming. Abilities like XT-002's Typmanic Tantrum attack are used on a particular schedule, and so having Divine Sacrifice ready for the moment of truth will make your survivability skyrocket. If you're searching your bars and hotkeys for Divine Sacrifice when the damage is already present, then you're already too late.
Even if we do manage to reduce some of the incoming damage that our team mates receive, we're still stuck with healing that missing life back to full. Flash of Light can be useful if used properly, due to its quick casting speed and low mana cost. Holy Light may have started out as the tank-healing spell of the year, but it also packs a secondary raid healing punch via Glyph of Holy Light. The splash of healing from GoHL has added up to 15% of my healing before, especially when cast on a pack of melee DPS who are stacked behind a boss. FoL paladins are usually the strongest raid healers, as they're able to cast fairly strong heals 25% faster than their HL siblings. However, even with their quick and potent heals, an FoL paladin will still be supporting a true AoE healer.
I like to use glyphed Holy Light for raid healing because the glyph can literally boost the value of a Holy Light by 50% if the effect is used to its full potential. When fighting Valithria, I now stand next the boss (beacon on Valithria) and spam Holy Light on myself. The splash heal from GoHL will end up doing a massive amount of healing, since it apparently double-dips with whatever healing modifiers you currently have active. While it can be hard to find a group of 4-5 people in close enough proximity to gather the full benefits of GoHL, so try to aim your heals towards areas of heavy player concentration. This will give you the best chance of minimizing the number of wasted glyph procs. The 'tank and melee' cluster is usually a good spot to throw a Holy Light into, as there are typically several targets there who could use some healing.
The key problem with trying to have a paladin heal the raid through AoE incoming damage is the idea of 'time until healed'. If a holy paladin was tasked with casting a heal on 10 raid members, that would be 9 Flash of Lights at the very least to touch every raider (one gets healed via Beacon). It would take at least 9 seconds to cast that many Flash of Lights, and a decent FoL won't heal for more than 5-7k healing. Let's say you heal player 1, then player 2, then player 3, etc. By the time you've finished healing player 10 and you're back around to player 1, they've been waiting 10 seconds before their next heal arrived. Considering AoE damage pulses are ticking for 1.5-2.5k damage in current content, player 1 would either be dead or hanging on by a thread. They'll need more than an FoL to save them, and while you're taking your time casting a Holy Light on them, player 2 is already dead. A paladin's 'time until healed' value in a raid situation is simply too high to handle healing through appreciable AoE damage. However, we can assist other healers as they focus on their multi-target healing.
Obviously as multiple players take damage, other healers will be using their AoE spells, but some players may be out of range or not stacked up to receive healing. The key is to pick out the person who can use the healing the most, and then heal them to full so that the AoE healers can focus on handling the aura damage. If the incoming raid damage is high, you'll definitely want to lean on your most powerful heal to bring the raid's green bars to 100%. If the incoming raid damage is low and predictable, you can save a bit of mana by just using Flash of Light to heal through the damage by targeting the lowest HP player and bringing them back up. You can leverage Holy Shock to assist with raid healing as well, especially since raid members usually don't have dedicated healers assigned to them. Quickly healing a wounded player to full will allow your raid healers to focus on healing the entire group instead of stopping to focus on a single target, which keeps you both doing what you're best at. You'll also be healing the tank the entire time via Beacon, so you haven't even neglected your primary duty.
The 'time until healed' factor becomes crucial when determining what healing strategy to use against raid-wide damage. If you have to cast a spell on all 9 or 24 other players in your raid, it will take forever to get anything done. We can only do our best by using Holy Light and its glyph to cover as much ground as possible, or using Flash of Light to do some 'maintaining' while another healer focuses on the heavy lifting of healing the entire raid. We've got access to powerful cooldowns and our ability to quickly save targets that are low on life can play a huge role in the raid's healing toolkit. If a player dips low in life by standing in the fire or something similar, we have large, quick, efficient heals for getting them stable again. We're the trauma surgeon, while druids and priests play the role of general practitioner.
We can't heal through the Twin Val'kyr alone, but when complemented with another healer, we can make their lives easier by providing ample tank healing, add significant amounts of raid healing via JoL and GoHL, and use our quick and powerful heals to save any target that dips low. Raid damage fights don't have to be a nightmare for you, as long as you know how to stay calm and do focus on doing what you do best.
The Light and How to Swing It (Holy Edition) is dedicated to helping holy paladins become the powerful healers that we're destined to be. If you're new to the paladin's healing ways, you can learn the ropes with our Holy 101 article. We also have information on how to keep a tank alive, or how to heal a raid when necessary. Tanking is a job, DPS is a craft, but healing is truly an art.