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Updated: 26th August 2017
This guide is a combined effort of both M+ guide writers, Herux and myself containing all the ways mages can deal with the various mechanics in m+ dungeons. If there is anything you would like to add, feel free to let us know!
Links
Black Rook Hold
Cathedral of Eternal Night
Court of Stars
Darkheart Thicket
Eye of Azshara
Halls of Valor
Maw of Souls
Neltharion's Lair
Return to Karazhan: Lower
Return to Karazhan: Upper
The Arcway
Vault of the Wardens
Black Rook Hold
Spellsteals
http://www.wowhead.com/npc=100486/risen-arcanist : http://www.wowhead.com/spell=197797/arcane-blitz This mob also appears in the fight with the 2nd boss, http://www.wowhead.com/npc=98696/illysa ... ies:mode=m.
Blinks
http://www.wowhead.com/npc=101839/risen-companion : http://www.wowhead.com/spell=225962/bloodthirsty-leap
Ice Blocks
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Amalgam of Souls
http://www.wowhead.com/spell=196587/soul-burst A common strategy is to ignore the adds and have the whole group use immunities to survive the soul burst.
http://www.wowhead.com/spell=194966/soul-echoes Removes the fear puddles instantly.
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Illysanna Ravencrest
http://www.wowhead.com/spell=197546/brutal-glaive Removes the 30sec dot relieving an insane amount of pressure on your healer.
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Smashspite the Hateful
http://www.wowhead.com/spell=198079/hateful-gaze It is also possible to to block the path if targeted on an ally, soaking all the damage they would otherwise take.
http://www.wowhead.com/npc=98970/latosius#abilities
http://www.wowhead.com/spell=201733/stinging-swarm Drops the swarm instantly which relieves practically all the pressure from your healer in this phase.
http://www.wowhead.com/spell=202019/shadow-bolt-volley On high keys this can 1 shot you if you are not using additional shields.
Cathedral of Eternal Night
Spellsteals
Blinks
Ice Blocks
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Agronox
http://www.wowhead.com/spell=236524/poisonous-spores : Resetting the stacking debuff is very beneficial for your healer
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Trashbite the Scornful
http://www.wowhead.com/spell=237726/scornful-gaze : Not only does it prevent the damage, it also does not break the bookshelf you would typically have to stand behind. This means you do not get the extra book adds which can be an incredible pain to deal with. Also extends the soft enrage timer.
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Domatrax
http://www.wowhead.com/spell=234107/chaotic-energy : Immuning this cast is only necessary on very high keys to extend the length the shield from the Aegis is available.
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Mephistroth
http://www.wowhead.com/spell=234382/creeping-shadows : Resetting the stacks in the intermission debuff will be greatly appreciated by your healer.
Court of Stars
Spellsteals
http://www.wowhead.com/npc=111563/duskw ... #abilities : http://www.wowhead.com/spell=209033/fortification
Blinks
http://www.wowhead.com/npc=105699/mana-saber : http://www.wowhead.com/spell=209516/mana-fang
Ice Blocks
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Captain Gerdo
http://www.wowhead.com/spell=207278/arcane-lockdown : Instantly removes the debuff instead of having to jump 3 times or waste a healer GCD.
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Advisor Melandrus
http://www.wowhead.com/spell=209676/slicing-maelstrom : It is typical to immune one of the later times this ability is cast due to the immense amount of healing required from your healer. It is also beneficial to run into a http://www.wowhead.com/spell=224333/enveloping-winds at the same time, to clear up some space in the room.
http://www.wowhead.com/npc=104278/felbo ... ies:mode=m
http://www.wowhead.com/npc=104278/felbo ... ies:mode=m : Removes the very high damage ticking debuff if you fail to LOS (Line Of Site) it.
http://www.wowhead.com/npc=104274/baalgar-the-watchful
http://www.wowhead.com/spell=207980/disintegration-beam : Removing this debuff not only allows you to keep your damage high but also removes the damage you are taking from the channel. Only really beneficial if you have been targetted twice or more times in a row so the stacks are at 6+.
SUPER SECRET: If you LOS as the cast finishes, he will re-target the channelled beam onto another member of the group. Great for avoiding the dps loss.
Darkheart Thicket
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Archdruid Glaidalis
http://www.wowhead.com/spell=196376/grievous-tear : Removes the debuff and therefore the requirement to be healed to above 90% hp.
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Shade of Xavius
http://www.wowhead.com/spell=200238/feed-on-the-weak : Inflicts damage every 1 second of the 5 second channel. Your healer should be able to keep on top of these but they may call for you to block depending on other mechanics they are dealing with.
http://www.wowhead.com/spell=200185/nightmare-bolt : Removes the annoying silence circle. Can also be blocked while it is travelling and therefore ignoring the damage portion of the spell.
http://www.wowhead.com/spell=200050/apo ... -nightmare : Only immuned if you are either not at full HP when this is casting or if the key is so high that it will 1 shot you at full HP.
Eye of Azshara
Spellsteals
Blinks
Ice Blocks
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Warlord Parjesh
http://www.wowhead.com/spell=192131/throw-spear : A random, extremely deadly dot.
http://www.wowhead.com/spell=192094/impaling-spear : It is possible to soak this spear exactly like the adds would if for some reason you do not have adds alive at this point.
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Lady Hatecoil
http://www.wowhead.com/spell=193597/static-nova : Saves a platform from being destroyed which can be an issue in very high keys since you come close to running out.
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Serpentrix
http://www.wowhead.com/spell=191855/toxic-wound : Removing this debuff means you do not have to move for the entire duration and inevitably tanking your dps.
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Wrath of Azshara
http://www.wowhead.com/spell=197365/crushing-depths : Soloing this ability vastly reduces the damage the group takes overall. The healing requirement ramps up during the entire fight so it is incredibly OP being able to solo them.
Halls of Valor
Spellsteals
http://www.wowhead.com/npc=96574/stormforged-sentinel : http://www.wowhead.com/spell=198745/protective-light
Blinks
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Fenryr
http://www.wowhead.com/spell=196497/ravenous-leap can also be avoided with blink but it is important to not blink into another player who is also targetted.
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God-King Skovald
http://www.wowhead.com/spell=193659/felblaze-rush can be avoided completely with a well timed blink.
Ice Blocks
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Hyrja
http://www.wowhead.com/spell=191976/arcing-bolt : If you are targeted with this ability, make sure to blink away from the group and then block. This ability chains to nearby players even if the first target is immune.
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Fenryr
http://www.wowhead.com/spell=196838/scent-of-blood : If targeted, sit in the entire Ice Block close to the boss so that melee can retain their dps uptime.
Invisibility
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Fenryr
http://www.wowhead.com/spell=197556/ravenous-leap : Fenryr will always jump the to target the farthest away. If you cast http://www.wowhead.com/spell=66/invisibility as soon as the animation is finished, you will disable the leap entirely.
http://www.wowhead.com/npc=95842/valarjar-thundercaller
http://www.wowhead.com/spell=198595/thunderous-bolt and http://www.wowhead.com/spell=215429/thunderstrike can both be immuned as they do insane amounts of damage on high keys. Typically, you can survive either of them so it is wise to save block for those rare times both are cast on you at the same time which will 100% end in a 1 shot.
Maw of Souls
Spellsteals
http://www.wowhead.com/npc=98919/seacursed-swiftblade : http://www.wowhead.com/spell=194615/sea-legs Has a high chance to deflect spells (even spellsteal) so successfully purging is very rng. Worth the effort though.
Blinks
Ice Blocks
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Harbaron
http://www.wowhead.com/spell=198551/fragment can be immuned to avoid spawning any adds on you. However, you must stay inside the http://www.wowhead.com/spell=45438/ice-block until the cast is completely over or he will retarget/cast it again on you.
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Helya
http://www.wowhead.com/spell=227233/corrupted-bellow : If you are too slow at moving (or your blink doesn't send you anywhere), you must immune this damage as it is VERY high even on low keys.
http://www.wowhead.com/npc=97043/seacursed-slaver
http://www.wowhead.com/spell=194674/barbed-spear : Is an incredibly annoying ability. If you healer is too busy to dispel, make sure to remove the debuff as being pulled into the group can very easily result in death from another mobs abilities.
Neltharion's Lair
Spellsteals
Blinks
Ice Blocks
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Naraxas
http://www.wowhead.com/spell=210150/toxic-retch : A very hard hitting dot. Helps your healer out a lot to remove especially if you have just dropped a http://www.wowhead.com/spell=205549/rancid-maw.
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Dargrul
http://www.wowhead.com/spell=200404/magma-wave : If you don't want to hide behind http://www.wowhead.com/spell=200551/crystal-spikes for whatever reason.
Return to Karazhan: Lower
Spellsteals
Blinks
Ice Blocks
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Maiden of Virtue
http://www.wowhead.com/spell=227508/mass-repentance : Removes the need to pick up the http://www.wowhead.com/spell=227789/sacred-ground debuff which ticks for an incredible amount.
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Moroes
http://www.wowhead.com/spell=227742/garrote : Removes the stacks of the ticking dot which lasts the entire fight, draining your healers mana. Generally save for when you have multiple stacks of the debuff.
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Attumen the Huntsman
http://www.wowhead.com/spell=228852/shared-suffering : Still divides the damage equally even if you immune it.
http://www.wowhead.com/spell=227404/intangible-presence : Remove only if you have the specter on your back (it is quite hard to notice) otherwise you will hit your entire group with aoe.
Additional
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Attumen the Huntsman
http://www.wowhead.com/spell=227363/mighty-stomp can be out-ranged if you are farther than 30 yards away.
Return to Karazhan: Upper
Spellsteals
Blinks
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Shade of Medivh
http://www.wowhead.com/spell=227615/inferno-bolt can be avoided if you blink at the end of the cast while the bolt is travelling.
Ice Blocks
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Shade of Medivh
http://www.wowhead.com/spell=227592/frostbite : If your group has run out of interrupts, you can preemptively Ice Block to prevent both the damage and stun.
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Mana Devourer
http://www.wowhead.com/spell=227502/unstable-mana : Collecting as many orbs as possible and then blocking them off is a perfect way to prevent the boss from reaching full mana. If you managed to obtain a rat mount through out the instance, you can remain mobile while in Ice Block allowing you to potentially soak all of the orbs during this phase.
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Vizaduum
http://ptr.wowhead.com/spell=229159/chaotic-shadows : Removing this debuff causes http://ptr.wowhead.com/spell=229161/explosive-shadows to spread out around your character which do a lot of damage. Make sure to drop these far away from other players to avoid killing them.
The Arcway
Spellsteals
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Advisor Vandros
http://www.wowhead.com/spell=203176/accelerating-blast
http://www.wowhead.com/npc=98733/wither ... #abilities : http://www.wowhead.com/spell=210662/unstable-flux
http://www.wowhead.com/npc=105617/eredar-chaosbringer : http://www.wowhead.com/spell=211632/brand-of-the-legion and http://www.wowhead.com/spell=226285/demonic-ascension
Blinks
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Ivanyr
http://www.wowhead.com/spell=196804/nether-link : Blink next to other players at the end of the cast to reduce the size of the puddle
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Naltira
http://www.wowhead.com/spell=200227/tangled-web : You can blink the chain while you are being pulled across the room, breaking the tether instantly.
Ice Blocks
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General Xakal
http://www.wowhead.com/spell=197810/wicked-slam : A very hard hitting AoE damaging ability.
http://www.wowhead.com/npc=98770/wrathguard-felblade
http://www.wowhead.com/spell=211756/searing-wound : A very hard hitting dot which can be applied more than once.
Additional
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Ivanyr and Vandros
http://www.wowhead.com/item=132452/sephuzs-secret is very good on these fights due to them always casting an ability.
http://www.wowhead.com/npc=105651/dread ... #abilities
http://www.wowhead.com/spell=211771/prophecies-of-doom can be out-ranged if you are farther than 30 yards away.
http://www.wowhead.com/npc=103130/timeless-wraith can be instantly interrupted if you aggro them with http://www.wowhead.com/spell=54793/frag-belt.
Vault of the Wardens
Spellsteals
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Inquisitor Tormentorum
http://www.wowhead.com/spell=26043/batt ... sed-by-npc used by the adds in the North-West corner.
Blinks
http://www.wowhead.com/npc=109017/cordana-felsong
http://www.wowhead.com/spell=197422/creeping-doom : You can blink over the spirit wall instead of having to find the gap like the rest of the pleb classes.
Ice Blocks
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Ash'Golm
http://www.wowhead.com/spell=192519/lava can be cleared by walking over multiple patches and blocking the debuff off.
Additional
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Inquisitor Tormentorum
http://www.wowhead.com/spell=190356/blizzard ticks removes http://www.wowhead.com/spell=200904/sapped-soul instantly if precast.
http://www.wowhead.com/spell=130/slow-fall is a great ability to use when getting rid of http://www.wowhead.com/spell=200904/sapped-soul