Well, time for part three of my guide to Trial of the Crusader. This time I'm going to cover the Faction Champions. This is potentially a much tougher fight than the previous two, depending on just how much PVP experience you have. Luckilly for you, I've done this fight several times now, and have some helpful tips to impart.
So, a brief synopsis is in order. Basically, this is a mock-pvp match. Your group of 10 or 25 people will face off against 6 or 10 members of the opposing faction. The NPCs that you're fighting will have a ton of health, will use a wide range of attacks and CC that would normally be available to their class, and will hit you for about as hard as a well geared PVPer would. The fight ends when you kill all the opposing Faction Champs that get sent out after you.
The first thing you've got to realize is that this isn't a DPS race. This fight is all about survival and CC. As with an Arena match, the general tactic is to CC some of your enemeis while you burn down others. Unfortunately, Shadow Priests lack strong burst, but we can still contribute to this fight. Let me break it down for you:
Crowd Control
Any CC that you use on a Faction Champ works with normal PVP rules. This means that it has a max duration of 10 seconds, and multiple uses of the same form of CC build up Diminishing Returns.
Now, we unfortunately lack tall cliffs, and all the Faction Champs are immune to Mind Control anyway, so you can throw that spell out the window. They are fully vulnerable to Psychic Scream, Psychic Horror, Mind Flay and Silence however.
I generally find that I'm using PS on cool down during this fight. I use it early to break up some of the opposing melee. The AI controled casters have a tendency to just sit still and cast spells, so run by them and PS them to take them out of the fight for a few seconds. Silence I use on the Healers, as my guild tends to blow them up first. I find I use Psychic Horror about 2 times a fight, and I tend to reserve it for either the opposing Rogue or Deathknight. Remember that PH has a 10 second Disarm, which can really help when enemy melee is beating on your healer. Finally, the 50% snare from Mind Flay works perfectly in here. It's a great tool for peeling melee off of a healer, if used correctly.
Survivability
This is a bit odd to consider, but for a clothie caster, we can be suprisingly resiliant. Dispersion is amazing during this fight, as it's not unusualy to have 2-3 of the faction champs focus on you. They like to use Slowing effects as well, and Fade comes in handy here. I also toss up Vampiric Embrace and toss DoTs around, as this has the nice side-effect of giving me a steady stream of heals.
We can also drop out of Form to heal, or pass out Power Word: Shield bubbles while in form. This is amazing utility during this fight, and if you see a team mate gettling low on health, HEAL THEM. It is entirely possible for the Faction Champs to CC all of your healers. When this happens, so long as you're not CCed yourself, then it is your fault if somebody dies.
Dispells Away!
One very powerful mechanic on this fight is the ability to Dispell and remove Diseases. You're going to see MANY DoTs, silences, slows, stuns, ect. on your team-mates. You've got the ability to remove many of them, so use it. Passing out Disease cleanses when you're fighitng the DK is also particularly useful.
Another thing to note, depending on the type of healer you face, offensive dispells can be very useful. Is that annoying Druid rolling HoTs? Dispell em. Did that Paladin just Bubble up? Mass Dispell it and kill it. Did the enemy Shaman pop Heroism / Blood Lust? It's Mass Dispell time again. You've got a very nice tool here, use it.
Other Tips
The first thing you should do is stay mobile. If you just stand still you'll eventually get focus fired, but if you and the raid moves around a lot, the NPCs tend to spread out a bit, and the risk of getting instantly killed by concentrated attacks is vastly reduced.
Next, at some point in time you're going to get locked out of your Shaodw School. It just happens on this fight, unless you're really lucky. When this happens, don't panic. You can either start healing, or you can use your Holy attack spells. Either way, we've got something semi-useful to do on this phase.
You can also do a few things to manipulate the opposing UI. Cast Shadow Fiend early and often, as the AI will often target a pet over a player. The agro dump mechanic from Fade is somewhat useful as well, as it will occasionally cause the AI to switch to a different target. This is most useful if you and your raid stays spread out, as you can cause a melee NPC to run across the board a couple times with proper agro dump and taunt usage.
Overall, this fight is about team-work. You and your raid have to work together and communicate. Don't be suprised if you wipe several times though, as this is a complicated fight with many possible strategies to be employed for a successful kill.