The only Dragon Soul boss strat I have left is Madness of Deathwing. ...Here goes. I don't suspect it'll be brief.
First things first: A note on speccing and gearing for this encounter
Haste is a tricky aspect of this encounter. Part of the mechanics for this encounter gives us an additional 20% Haste. Since you can Bloodlust twice, have at least one Haste Cooldown with Icy Veins, and can spec for other haste abilities such as Netherwind Presence and Early Frost, it's quite easy to bring your Frostbolt under the GCD.
As Frosties may or may not know, there is a sort of soft Haste-Cap, where your Early Frost Frostbolt will be at exactly 1.0 seconds during Icy Veins. Assuming that your raid has the 5% Haste Buff, the Haste ratings for this cap are 1144 with 2/3 NWP, and 1424 without NWP. If you are at the Haste Cap, you will quite often be under the GCD. Here are some cast times I wrote down. These are all with 0 Stacks of Stolen Time, so if a spell is within .01 second of the GCD, it will likely fall under the GCD at higher Stacks. Without further ado:
Haste-Capped, Raid buffed, no CDs: 51.68% Haste
FB: 1.32 s
Haste-Capped, Raid buffed, Icy Veins active: 82.01%
FFB: 1 37s
Haste-Capped, Raid buffed, Bloodlust/Heroism Active: 97.18%
Haste-Capped, Raid buffed, Icy Veins & Bloodlust Active: 136.49%
As you can see, it's very plausible to have Frostbolt fall under the GCD, even without Early Frost.
I thought about ways to fix this; it probably is no help in this encounter to have Early Frost, and could be done without. And yet, Frostbolt still comes in danger of falling under the GCD if Bloodlust is active, and will definitely fall under the GCD if BL/IV are active simultaneously.
We could also lower our Haste levels dramatically, and spec out of NWP (if we're specced into it; I generally don't anymore). But, if you look at the cast time of FB when Bloodlust and Icy Veins are up, it's 0.845 seconds; you'd have to spec out of a lot of Haste, and it would be for nothing more than a fringe situation that only comes up twice. Not to mention, since virtually every damned piece of Tier 13 Cloth gear has Haste, it could be difficult to do that without replacing our current gear for inferior pieces in the first place.
Thus, I make the following recommendations:
1. Optionally, spec out of Early Frost. One GCD Frostbolt every once in a while won't kill us; but, if you can make a spec that doesn't include it, go for it.
2. Don't bother removing Haste. While I do recommend taking Impact over NWP this tier (and especially for this encounter), don't make a separate reforge or gear set for this fight. ...Except trinkets. If you're running a Haste Trinket, I would recommend switching it out if you have anything comparable. Good trinkets for this encounter are Will of Unbinding, Variable Pulse Lightning Capacitator, and Cunning of the Cruel. I would super-duper not-recommend Insignia of the Corrupted Mind - you don't need a few-thousand points of Haste messing with you mid-fight.
3. If/When your Frostbolt falls under the GCD, switch to Frostfire Bolt.While its chance to Crit will be lowered, it can still proc Fingers of Frost, and it certainly can still Crit, proccing Ignites - not a bad tradeoff at all. Now, we don't have to worry about having Icy Veins and Bloodlust active simultaneously.
If your raid progression is on this fight, I would recommend this spec: http://www.wowhead.com/talent#oZfc0bZcfMzsIszro:
Normally, I hate Reactive Barrier; but, it's honestly the only thing we can spec for instead of Early Frost that won't be a waste. Deathwing doesn't heal himself, nor does our Water Elemental come in danger of dying, so Permafrost is out. We don't need to snare anything, so Improved Cone of Cold and Shattered Barrier are out. We'll never need a 40-yard Ice Lance, and there are no moving adds without aggro tables, so we don't need to max out Ice Shards. Thus, Reactive Barrier is the only reasonable choice.
I would spec for Impact, as it can be a huge boon for the AoE sections of this fight. If you can, make sure your Haste Rating is at least 1424. You can still spec for NWP and probably not see a huge difference, although I don't like to admit it; thus, if it will be too inconvenient to spec out of NWP, go ahead and keep it instead of Impact.
Naturally, if you have this fight on farm, just spec and gear in whatever way is most convenient for you.
The Encounter: Phase 1
There are four platforms, which Deathwing hangs onto with his arms and wings. Before we kill Deathwing, we need to knock out both arms and both wings - hereafter "limbs" - one representing each platform. Each platform goes like this:
A few seconds after reaching the platform, Deathwing summons a Mutated Corruption on the opposite end of his limbs. The Mutated Corruption needs to be dealt with by both tanks (unlike the limbs which don't attack and have no aggro tables, so wait for the tank!). Mutated Corruptions will occasionally Crush an opponent, hitting anyone who is lined up vertically with its target; so, spread our horizontally as best as you can, trying to make sure no one is in front of you or behind you.
At some point while fighting the Mutated Corruption, Deathwing will cast Elementium Bolt. The bolt itself is an add which can be attacked. If the bolt lands on your platform, it will deal a TON of damage to your raid, and will probably kill people who aren't topped off/using defensive cooldowns, so don't let it happen unexpectedly.
After dealing with the Corruption and Bolt, the raid will go back to killing the limb. Deathwing will eventually channel a spell called Cataclysm, which is a mini-enrage for each platform. We'll need to kill the limb before the cast is finished, or the group will wipe; but, we also need to deal with two different sets of adds during this part:
- Regenerative Bloods, which will spawn about 90 seconds into a platform. They need to be picked up by a tank and AoE'd down by the group, because they place a stacking debuff on whomever they attack, and will also regenerate all of their health if not killed within a certain timeframe.
- Blistering Tentacles, which will spawn when the limbs are at 70% and 40% health. The tentacles place a stacking debuff on the raid which deals damage to everyone, and increases over time. They need are also immune to any attack that can hit more than one target, so they need to be focused with single-target attacks and killed immediately.
Also, Deathwing's limbs are constantly casting Burning Blood, which deals raid-wide Fire damage. This damage is trivial at first, and ramps up as the limb's health drops.
Repeat this process four times and we've finished Phase 1.
However! What makes this Phase interesting is that we have four special raid buffs placed on the group by our Dragon buddies, which help us with healing, damage, defense, and add control. Here they are:
Ysera: Increases Healing by 20%, and allows all players to use a Defensive Cooldown called 'The Dream", which lowers all damage taken by 50% for a few seconds.
Alexstraza: While she is active, she will kill the Blistering Tentacle adds extremely quickly (about 5 seconds), allowing your raid to continue DPSing the limbs instead.
Nozdormu: Increases Haste by 20%, and also places a circular AoE on the platform called "Time Zone." The Time Zone slows the attack speed of all enemies within it by 50%, making it an ideal place to tank the Regenerative Bloods. The Time Zone will also slow down the trajectory of the Elementium Bolt, allowing the raid to destroy it before it lands.
Kalecgos: Increases Damage by 20%, and all attacks proc an ability called Spellweaving, which deals additional damage to enemies near your target. This makes AoE spells very powerful, allowing us to kill the Regenerative Bloods very quickly.
Each Dragon represents a specific platform, and once the limb on a platform has been killed, the corresponding Dragon's buff will be removed from your raid until Phase 2. The platforms can be dealt with in any order, and it's up to you to be aware of how the situation changes. I'll do my best to go over my thought process for each platform, from the beginning to the end:
- Don't be afraid to use DPS cooldowns as they come up, unless Kalecgos's platform is down; in which case, I'll want to try and save them for the Elementium Bolt and Blistering Tentacles.
- If you have The Dream from Ysera, just use it on cooldown in Phase 1. Save the healers some heartache and just do it.
- Be sure to spread out horizontally when the Mutated Corruption spawns. Also, I rotate my camera so that I can see the Corruption and the Limb, as my Water Elemental is frequently in range to cast Freeze on the limb, but not the Corruption. Don't wanna be missing out on FoF procs!
- When the Bolt comes down, switch to it immediately. If we have Nozdormu's platform up, the Bolt won't hit right away, so I don't need to worry about how to defend against the impact. Speaking of Impact, the Bolt is very close to the limb at this time, so be sure to spread Ignite to the Limb for additional damage.
On the other hand, if Nozdormu's platform is down, I'll need to take necessary precautions. If I have Ice Block, I'll cast it right before the Bolt lands and prevent all damage, then DPS the bolt right away. Otherwise, I'd turn on all my cooldowns (The Dream if I have it, Ice Barrier, Mage Ward, and Mana Shield), then get as far away as possible. After the Bolt lands, I'll Blink back in range and DPS the Bolt as hard as I can.
- Once the Corruption is dead, focus on the limb. I try my best to get into the Time Zone aura (if Nozdormu is still up).
- When the Bloods spawn, I immediately cast Blizzard immediately. If I get BF+FoF+Impact, I'll try and hit the target with the most HP with a Frostfire Bolt, then spread Ignite to all the rest of the Bloods, at which point I'll continue with Blizzard. For one set of slightly stronger ticks, I also use Pet Freeze if it's ready.
A note: spreading Ignite instead of using continuous Blizzards may be a DPS loss if Kalecgos's platform is still up, as you're losing about two seconds of Spellweaving on each individual target. Unfortunately, the DPS numbers are super high, there are many variables, and the encounters are long, so I can't test this. However, if Kalecgos's platform is down, you'd be crazy not to spread Ignite.
- When the Blistering Tentacles Spawn, I'll keep DPSing the limb if Alexstraza is up. If she's down, however, it falls to us to kill them. I'll help the melee DPS out by hitting the ones in the far back so that they don't have to move as much. If the Tentacles are out at the same time as the Bloods, I'll focus the Tentacles first, as they are causing more damage to the raid overall. If Kalecgos is down, I'll make a mental note to save powerful cooldowns for the tentacles.
- After the first Blistering, the damage from Burning Blood begins to become noticeable, so I'll use Ice Barrier (and The Dream if I have it) to prevent as much damage as possible. If things begin to get desperate, I'll use Evocation to heal myself, and even Mage Ward (I wouldn't do this until things start getting really bad though, as Mage Ward usually drops off before the GCD is even finished!).
- When the limb dies, we can switch platforms. If we're jumping two platforms over in any direction, my strategy will change depending on one or two things.
If we're skipping a platform where a tentacle is still alive, I don't hesitate to cast anything I can at it. My priority is:
1. Deep Freeze
2. (Brain Freeze) Frostfire Bolt, to gain additional stacks of Stolen Time
3. (FoF) Ice Lance
4. (Brain Freeze) Frostfire Bolt, if I already have 8-10 stacks of Stolen Time
5. (Early Frost) Frostbolt
6. Fire Blast
7. Ice Lance
This is especially important with Will of Unbinding, since the stacks fall off after only ten seconds.
If we're skipping over a platform that has already been completed, I cast Blink to move across the platforms as quickly as possible. I also switch to Mage Armor until just before I'm about to reach my destination, to try and get as much Mana back as possible, too.
The Encounter: Phase 2
Phase 2, thankfuilly, is a very short portion of the fight. Hop on over to Ysera's platform and Deathwing's head will fall to the ground. Start to kill him, and he will spawn two different types of adds:
1. Elementium Fragments, which put a debuff on random players called Shrapnel. Shrapnel will absolutely kill a player without a Tanking cooldown/Guardian Spirit, so be sure to use The Dream to mitigate the damage. The spawn location of the Fragments is random; if you're using Impact, be partial to Fragments that are right next to each other, as you can get some extra damage out of it.
2. Elementium Terrors, which need to be tanked in the time zone. Make sure you let the tanks pick them up before touching them, as they place a very, very dangerous stacking debuff on anyone they attack. Be sure to focus down one at a time.
These adds are spawned on specific timers, so if there are no adds up, be sure to burn Deathwing as much as possible. If your raid still has Bloodlust, use it some time after killing the Terrors - either the first set that your raid kills or the second set. DW will likely hit his enrage before you can kill a third set of adds, so if you didn't do it the first time, do it the second time! Once you pop Bloodlust, you'll probably be burning the boss, in which case, ignore any new adds that spawn at this time.
A last note: When to use Bloodlust?
Simply put, there's two ways to handle Bloodlust:
1. Use it at the start of the encounter, and then it'll be ready to use again on Phase 2
2. Save it for a sticking point in Phase 1. For example, my raid group did the platforms in the following order: Ysera, Alexstraza, Nozdormu, Kalecgos. This means we had only one Bolt we couldn't kill before it landed. Back when we were still working on the fight, our tanks did not have their 4t13 sets, and mustering up the cooldowns to survive was hard...not to mention the Corruption could usually kill the tank afterwards by doing some nasty stuff that I didn't mention in this strategy guide. So, we used Bloodlust on the fourth platform to try and kill the Corruption before the Bolt landed, preventing the possibility of the Corruption killing raid members immediately afterwards.
If you're going to use it for a sticking point, take some time to find out what they are, and how Bloodlust will help.
As a Frost Mage, Your Ice Barrier, as usual, is the biggest advantage you can bring, and it's nothing to scoff at in this encounter, either. The end of each platform can get rough for your healers, especially after Alexstraza is down. Anything you can do to take some of the weight off them is good. You can also Ice Block the largest amount of times - technically, at least four times - making you perhaps the most low-maintenance spec for surviving Elementium Bolts in the game, especially when factoring in your Ice Barrier for the times Ice Block is unavailable. Taking down Nozdormu's platform early should be no problem whatsoever for you.
As a pet class, you have a slight advantage in being able to spread your DPS. For example, if your raid triggers tentacles while bloods are coming, you can have your Water Ele attack a tentacle while your raid group deals with the bloods. Having Impact (if you specced for it) will keep you afloat for killing bloods in Phase 1 if Kalecgos is taken out early, and is also good for dealing with the adds in Phase 2. Admittedly, though, Fire can do this better; Impact for Frost is mainly a point we have over Arcane.
For Glyphs, I would recommend Ice Barrier, Evocation, and Blink. Ice Barrier...well, yeah. Evocation can be handy in emergency situations. although the fight is so long that we might wind up using Evocation for its intended purpose for a change. Glyph of Blink allows us to cross a platform as quick as possible when skipping platforms.
Hooray! These are all my strats for Dragon Soul normal. Here's to the possibility of seeing some Heroic Frost Mage strategies.