Players working their way into Faction Champs the first few times will be annoyed at the the level of randomness this encounter brings. Each week brings a different configuration of opposing faction champions and some time has to be spent to figure out initial crowd control and the like. When the encounter begins, their target priority and attacks appear to be random until one of your mages gets chain targeted and is knocked out in the space of seconds.
But don't forget that Faction Champs is a programmed encounter that relies on certain trends and conditions. When these conditions are met, certain actions are executed. If you can recognize and understand how it works, you'll get a better handle on surviving.
For more details, refer to this thread on Main Tankadin for a further analysis of their behaviour. This post will address what individual healers can do to increase their survivability as well as selected points from the thread that are most relevant for healers.
For all healers
Heal everyone: Okay, this is a no brainer. Threat is tied to the health of players. The lower your health, the more likely you are to get targeted. Just like in arena, the player with the lowest health will typically get the full assist train on them by the champions.
Cleanse often: Decurse, Dispel, and Cleanse. You may even wish to assign one person specifically to the job of dispelling. It's tied into the reason above. Even 1 or 2 ticks could be enough to cause a number of champs to focus fire you down. The less ticking damage you take, the better.
Use cooldowns early: Faction Champions is decided within the first three minutes. If your raid is alive with minimal casualties and you've been able to knock out at least 1 Champion, you're well on your way. The trick is to survive long enough. Cooldowns should be used early on when all Champions are still alive. Any raid saving cooldowns should be used.
Keep your distance: Again, this doesn't need to be said. If you spot a melee champion within several yards of you, start running away in the opposite direction and get in the clear.
Fade often: When that warrior or death knight starts barrelling down towards you, hit the fade button. Contrary to popular belief, there is an element of threat involved. Unlike other typical boss encounters, threat is not determined by damage nor healing. The rules for threat aren't like other encounters. Fade will still work.
Psychic Scream offensively: Don't save Psychic Scream for defensive use. If you're healing, there's a chance it's not going to go off and connect. I've experienced my share of missed screams. Of course you should try to scream if there's a rogue beating on you, but there's a chance that it will miss. My point is to not rely on Psychic Scream to get you out of a jam. Use it to break open clusters of champions if it is possible. But it should not be relied upon as a last ditch defense.
Keep Inner Fire up: The lower the absolute armor value, the higher the threat. Make sure the Inner Fire buff is always active.
Mind your Earth totems: When I go through this encounter on my Shaman, I usually drop a Tremor totem against when there's Champions that fear. However, if I know I'm pursued or if I see a dangerous Champion pursuing a raider, I'll drop an Earthbind totem to delay them.
Hex: If you can spare it, squeeze off a Hex on a target that's not likely to get hit such as the hunter or shadow priest. Hex has a long cooldown, so it's not something that can really be relied upon for constant use the way Polymorph would be. If it's free, go ahead and use it.
Bear form: Going to bear mode saves lives. I mentioned earlier that threat is tied in to armor value. It may not seem like much, but it should allow you to withstand an extra hit or two if you find yourself staring down a warrior.
Roots: Entangling Roots should be used specifically against melee targets. No point in locking up the hunter or the mage as they can still drill players from afar.
Cat form: On the other hand, if your screen flashes and you see someone pursuing you, shift to cat form and run. The closer you are to a target, the higher you are on the threat table. If you can afford to Dash away, do so. If you get yanked back by the pesky death knight or something, bear form is the next last ditch effort.
Bubble-sacrifice early: I'll be more specific here with the paladin cooldowns. Ideally, all of the paladins in your raid will have Divine Sacrifice. If you're being focused, don't hesitate to Divine Protection and Divine Sacrifice.
Hand of Protection: I caught myself before I could say use BoP. But keep Hand of Protection ready for casters who need them. Save it when they get pursued. This is especially important for players who are still crowd controlling certain targets. They need to be kept alive (at least until more Champions fall).
Want some more advice for working with the healers in your guild? Raid Rx has you covered with all there is to know! Looking for less healer-centric raiding advice? Take a look at our raiding column Ready Check.