Is Anti-Magic Zone useful?

Now that Unholy is viable for decent DPS in Dragon Soul, and is probably even better than frost for a lot of fights, one can ask if it is really useful to use a spec that includes Anti-Magic Zone (5/1/35) or if it is just better to go for the higher DPS specs like 7/1/33 or 5/3/33.

The Tooltip of Anti-Magic Zone reads: Places a large, stationary Anti-Magic Zone that reduces spell damage done to party or raid members inside it by 75%.  The Anti-Magic Zone lasts for 10 sec or until it absorbs (10000 + 2 * AP) spell damage.

At level 85, raid buffed in Heroic Firelands gear, and considering that the proc from Fallen Crusader (+15% Strength) might or might not be up, the maximum theoretical absorb should be between 55-60k spell damage. It doesn’t seem like a lot to say the least… But there is a trick, and a big one! It is actually possible to absorb much more damage, and I will try to explain as simply as possible how it works, when it should be used, and why it is very important to spec into it.

The following numbers are taken from our first Heroic Morchok 25 man kill this week. You can find the specific WoL here, as well as videos of our kill from Kinshar (Prot warrior PoV) and Beruthiel (resto druid PoV).

On Morchok Heroic, the boss summons his twin Kohcrom when he reaches 90% hit points. They have a shared health pool, and do the exact same abilities with a little time delay. As a result, the raid has to be split and act like to separate 12/13 man raids that will deal with the boss’ abilities separately. It is, in my opinion a decently well tuned encounter for a first heroic boss in Dragon Soul, that will test both your DPS and your healers.

Throughout the fight, either elemental will use a Stomp that deals physical damage split between all enemies within 30 yards, usually followed by a resonating crystal that deals massive shadow damage after 12 seconds to the 7 closest players. More damage is done the farther these 7 players are from the crystal when it explodes. What happens when Anti-Magic Zone is used right before the crystal detonates? Let’s take a more in depth look at the WoL logs to figure it out:

First AMZ cast:
[23:14:21.102] Shrakzyn casts Anti-Magic Zone
[23:14:21.102] Shrakzyn summons Anti-Magic Zone with Anti-Magic Zone
[23:14:21.343] Shrakzyn gains Anti-Magic Zone from Anti-Magic Zone
[23:14:21.343] Bogarl gains Anti-Magic Zone from Anti-Magic Zone
[23:14:21.352] Chaosdots gains Anti-Magic Zone from Anti-Magic Zone
[23:14:21.352] Rehr gains Anti-Magic Zone from Anti-Magic Zone
[23:14:21.352] Seforoth gains Anti-Magic Zone from Anti-Magic Zone
[23:14:21.416] Resonating Crystal Resonating Crystal Shrakzyn 32651 (A: 59278, R: 10214)
[23:14:21.416] Resonating Crystal Resonating Crystal Hugs 61285 (R: 40857)
[23:14:21.416] Resonating Crystal Resonating Crystal Chaosdots 13406 (A: 58094, R: 30643)
[23:14:21.416] Resonating Crystal Resonating Crystal Kinshar 51480 (A: 22063, R: 20429)
[23:14:21.416] Resonating Crystal Resonating Crystal Rehr 22436 (A: 59278, R: 20429)
[23:14:21.416] Resonating Crystal Resonating Crystal Bogarl 11426 (A: 34276, R: 30643)
[23:14:21.416] Resonating Crystal Resonating Crystal Seforoth 32651 (A: 59278, R: 10214)
[23:14:22.558] Anti-Magic Zone’s Anti-Magic Zone fades from Shrakzyn
[23:14:22.558] Anti-Magic Zone’s Anti-Magic Zone fades from Chaosdots
[23:14:22.558] Anti-Magic Zone’s Anti-Magic Zone fades from Seforoth
[23:14:26.137] Anti-Magic Zone’s Anti-Magic Zone fades from Bogarl
[23:14:26.137] Anti-Magic Zone’s Anti-Magic Zone fades from Rehr

- 5 people get the AMZ buff and 7 people get hit by the resonating crystal. The 2 players not affected by AMZ take respectively 61k and 51k damage from it.
- From the 5 people affected by it, 4 people are getting a 58-59k absorb and 1 person is absorbing 34k.
- The person who absorbed 34k  only took 11k damage on that crystal, meaning he still absorbed exactly 75% of the damage: 34/(34+11)=75.5% (he actually had barkskin active at that moment when checking in the logs).
- The 4 others affected by it here are getting a 58-59k absorb which is a 64-65% reduction in damage. We are not getting the full benefit of the 75% reduction because we are reaching the max absorb each.

Now for the second AMZ cast:
[23:17:20.609] Shrakzyn casts Anti-Magic Zone
[23:17:20.609] Shrakzyn summons Anti-Magic Zone with Anti-Magic Zone
[23:17:20.731] Shrakzyn gains Anti-Magic Zone from Anti-Magic Zone
[23:17:20.731] Bogarl gains Anti-Magic Zone from Anti-Magic Zone
[23:17:20.731] Chaosdots gains Anti-Magic Zone from Anti-Magic Zone
[23:17:20.731] Hugs gains Anti-Magic Zone from Anti-Magic Zone
[23:17:20.731] Zarazhas gains Anti-Magic Zone from Anti-Magic Zone
[23:17:20.731] Lildude gains Anti-Magic Zone from Anti-Magic Zone
[23:17:20.731] Rehr gains Anti-Magic Zone from Anti-Magic Zone
[23:17:20.731] Seforoth gains Anti-Magic Zone from Anti-Magic Zone
[23:17:23.195] Resonating Crystal Resonating Crystal Zarazhas 15557 (A: 46668, R: 8300)
[23:17:23.195] Resonating Crystal Resonating Crystal Chaosdots 9338 (A: 40462, R: 33200)
[23:17:23.195] Resonating Crystal Resonating Crystal Bogarl 11938 (A: 35811, R: 8300)
[23:17:23.195] Resonating Crystal Resonating Crystal Lildude 14525 (A: 43575, R: 24900)
[23:17:23.195] Resonating Crystal Resonating Crystal Rehr 13558 (A: 52842, R: 16600)
[23:17:23.195] Resonating Crystal Resonating Crystal Shrakzyn 16600 (A: 49800, R: 16600)
[23:17:23.195] Resonating Crystal Resonating Crystal Foamposite 58100 (R: 24900)
[23:17:24.306] Anti-Magic Zone’s Anti-Magic Zone fades from Shrakzyn
[23:17:24.306] Anti-Magic Zone’s Anti-Magic Zone fades from Bogarl
[23:17:24.306] Anti-Magic Zone’s Anti-Magic Zone fades from Chaosdots
[23:17:24.306] Anti-Magic Zone’s Anti-Magic Zone fades from Hugs
[23:17:24.306] Anti-Magic Zone’s Anti-Magic Zone fades from Zarazhas
[23:17:24.306] Anti-Magic Zone’s Anti-Magic Zone fades from Rehr
[23:17:24.306] Anti-Magic Zone’s Anti-Magic Zone fades from Seforoth
[23:17:25.087] Anti-Magic Zone’s Anti-Magic Zone fades from Lildude

- 8 people get the AMZ buff. 7 people take damage. From the 7 who take damage, only 1 person was not affected by AMZ . Thar person was the only one on that cast that took 58k damage.
- All the others affected by AMZ took 9-16k damage (Anoter mitigation cooldown was up at that moment). All 6 absorbed exactly 75-80% of the damage taken depending on if a Power Word: Shield was on them.

To conclude:
- AMZ will have its full effect on everybody affected by it if the damage is sudden and happens at the same time in the combat log. Full effect can mean 2 things: either a 75% damage reduction if the damage is less than the full absorb of an AMZ (55-60k raid buffed). Or a flat 55-60k damage reduction for everyone affected by it. In the specific examples above, AMZ absorbed  between 290k and 330k damage depending on the cast!
- AMZ will be useless on fights with gradual and/or constant AOE damage, like Ultraxion or any fight with a magic damage aura. In that case it will only absorb 55-60k damage spread between all players inside.

- If 25 players are in the AMZ when a sudden massive damaging magic attack happens, the spell has the potential of absorbing 1.375 to 1.5 million damage (yes, that much!).
- Taking this behavior into account, AMZ can soak a lot of damage and be an efficient raid cooldown on Zon’ozz bounces, Warmaster Blackthorn’s Big swirls and Deathwing’s elementium Bolts. Something to keep in mind as we all keep progressing through Heroic Dragon Soul!

It is pretty obvious from seeing these numbers that the spell can be extremely useful in Dragon Soul, and it is definitely nice to have the ability to use an efficient raid cooldown that needs to be coordinated with the healers and the paladins. When you need to use it though, keep in mind that it costs 1 unholy rune. So make sure that you have it available or that blood tap is off cooldown!

So, how was your own experience in using this spell so far? Do you think this increased raid utility will push many DKs to spec back Unholy after all of tier 12 specced Frost?

4 responses to “Is Anti-Magic Zone useful?

  1. I agree with this, we have been testing this out in DS and I am getting great feedback and positive force on AMZ during key fights- but ive notice that alot say that its usless in ultrazion but in my own opinion we’ve scene dramatic dmg reduction during his soft enrage, like i said it becomes a personal and guild prefrence from wiping so much … but in the end it seems to help quite alot :)

  2. Hey, just came across your blog when I was looking for someone doing a trinket analysis for unholy and found your list. Thanks for doing all the math so I don’t have to. I read through this post and it’s got some amazing info for amz which is one of the main reasons I switched from frost to unholy. I noticed the blog hasn’t got an update lately and I thought something useful might be a post on the use of AMS both in terms of survival and dps output. Almost every fight in DS has some absorbable magic damage which can be converted into free runic power. I think an in depth discussion of AMS usage in relation to dps output and survivabilty would be awesome. I’ve been kicking it around in my head lately so let me know if you want me to send you something.

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