Frost Mage raid bosses guide

This is a pretty straightforward boss. Make sure to save blinks to reach a safe spot when the AoE damage on the raid starts.

Make sure to use Barrier and Blink to move out from the raid if a bomb targets you and you need to go out and come back quickly.

Make sure to save Blink for Retch when you need to move with the raid to another position.

IMPORTANT: Make sure to use Alter Time or Barrier when you are the furthest player out for Dust Blast, it will deal heavy damage, and you might outrange your healers, so make sure you don’t end up dying.

Talents: You can pick Comet Storm instead of Splitting Ice

Notes: You want to use your Barrier as often as possible. There is a lot of raid damage, especially when you spread to bait the Stasis Trap and from boss Lighting.

IMPORTANT: Make sure to save a kick for the adds during the intermission, which happens at 75% and 50% health. A couple of adds will spawn, and Xy Acolyte is your priority target. Try to save a kick Xy Spellslinger. Debilitating Ray can be deadly if it's not kicked.

During the fight, the boss will spawn an add that needs to be burst down.

IMPORTANT: make sure to save Blink, Door of Shadows, or Soulshape for the Disintegration Halo Double ring Overlap.

During the encounter, the boss will create a shield on herself with a Siphoned Barrier, and it is crucial to burst down the barrier as fast as possible because it will do heavy raid-wide damage.

Make sure to save Alter time, and have Barrier or Mirror Images ready for the shield. Having Radiant Spark and Touch of the Magi with Rune of Power Ready to burst down Siphoned Barrier will be beneficial.

In this encounter, you will be fighting 2 targets most of the time. However, in the last phase, you will fight all 4 bosses simultaneously.

Make sure to save Blink \ Soulshape \ Door of shadows to move around the room if targeted by Night Hunter. The Ritualist and the Seed on Mythic are affected by a Shield, and you will need to break the shield with Night Hunter.

Keep in mind that the ritualist adds are a priority during the encounter.

IMPORTANT: Use your barrier as much as possible because this encounter is heavy with raid damage, and your healers will most likely be busy healing the seeds.

Do everything in your toolkit to survive Windswept Wings, and make sure to save Alter time for Hand of Destruction to stand far out and spread properly.

Kick Anima Bolt and Gloom Bolt as much as possible.

Talents: You can pick Comet Storm instead of Splitting Ice.

Notes: Make sure to save blink, door of shadows, or soul shape to move around the room if you need to move out for Motes or if you need to clear the motes with the Bomb.

There will be heavy damage during the intermission, and you can save Alter time to heal yourself back to full HP during the add phase.

On Mythic, there is a new mechanic called Alignment Shift, which means, unlike Heroic and Normal, that only pushes you back, you will also get pulled in on mythic difficulty. So, make sure to save blink or alter time to get back to your assigned group to deal with Alignment Shift.

IMPORTANT: Alignment Shift can either knock you back or pull you in, depending on which one you get. You want to save blink or alter time to deal with it accordingly to get back to your assigned group to stack with your friends for Alignment Shift.

During this encounter, your movement and positioning is key.

This is one of these encounters where you kinda have to “play it for yourself and get the feeling for “

But there are some things I want to emphasize.

The BEST ADVICE I can give to you is always to make sure that you are ahead of the boss during the intermission. You never want to find yourself in a position where you are chasing the boss, especially as a bomb holder.

ncantation of Swiftness is a REALLY nice QoL if you ever need a burst of movement during the intermission. Like Heroic, Crushing Prism should be placed in a good spot to try and slow the Motes.

Reclamation Form can be extremely deadly if you are not at full HP. It is super important that you keep yourself healthy with Barrier / Alter time / Mirror Images since it deals HEAVY raid-wide damage, and your healers might be far away from you or healing other players. Alter time is probably the best thing to deal with Reclamation Form.

IMPORTANT: On Mythic, if you are assigned to handle a bomb, you can see it as playing “Hot Potato“ the less time the bomb is on the ground, the better.

The bomb has a 30 seconds timer on it. While picking up the bomb, you will get a burst of damage and a debuff for 32 seconds, preventing you from picking up the bomb again.

Make sure to have a good amount of health before you pick up a bomb because if Earthbreaker Missiles are happening while you are picking up a bomb with low HP, you might be in danger.

During the intermission, you always want to be ahead of the boss, but make sure not to get knocked off the platform when the boss uses Detonation. If you find yourself with no blink available, alter time can be used to get yourself back into position.

Help your raid soak Befouled Barrier (deadly if you are not at full HP!)

Hopebreaker, Heavy raid-wide damage, make sure to save some a defensive for that, Shield, Mirror Images, Alter time. Blasphemy - make sure to find the opposite color as fast as possible, be CAREFUL with blink because it can trigger an explosion if you interact with someone who has the same color. Monstrous Soul has to be focused and burst down from 35%.

IMPORTANT: When you go into the Kingsmourne Hungers phase, you will leave a reflection of yourself upstairs that needs to be killed once you are done with the adds downstairs, so make sure not to over burst the reflections when you are upstairs and your friends are downstairs for Kingsmourne Hungers.

Alter time can be highly effective because the group downstairs will take heavy raid damage during Kingsmourne Hungers.

Dragon's Breath, Frost Nova, and Ring of Frost can be used if the small adds are getting too close to the center and you want to keep them CC'ed.

Blasphemy will be applied once or twice before the boss dies ( depending on your raid DPS ). You can Ice Block the explosion before the debuff goes off to let more people clear their Blasphemy debuff in the glowing bubble in the center. If you block the Blasphemy debuff, make sure to spread because you will deal a small explosion around you, and you need to be spread from someone else that is immuning Blasphemy so you won't die from the debuff.

Empowered Hopebreaker during the last phase can be EXTREMELY BRUTAL. Make sure to use everything you can to stay alive such as Greater invis, Kyrian Phial, Hearthstone, and Healing Potion.

Standard 2 Target cleave fight, once the boss reaches 100 energy, he will start casting Unto Darkness, which deals heavy raid-wide damage, so you might want to look at your health during the cast.

The boss takes extra damage during Unto Darkness, and it might be worth holding a cooldown for that. It should be 45 seconds into the pull.

IMPORTANT: Alter time is vital in this fight when Unto Darkness happens or when you have Cloud of Carrion on you. Greater invisibility is also a good choice.

Talents: You can pick Comet Storm instead of Splitting Ice.

Notes: This fight is all about killing the stars at the right time. Some things to keep in mind, you can only hit Dark Matter if you went inside a star and you are in the "delirium phase," so make sure to damage it as much as you can while you are inside. Also, make sure that you get out of the phase in a safe spot so you won't knock your friends away from the platform.

IMPORTANT: make sure to use blink \ door of shadows \ soul shape to reach the point you are assigned to for the intermission so you won't die from the Massive Bang. When you are inside the downstairs phase after killing the dark matter, there will be heavy raid-wide damage, so make sure to use whatever you have to stay alive, including Barrier, Images, etc.

If you are assigned to soak a core, use a defensive cooldown.

Alter time can be used to Negate Chains of Oppression.

Make sure to line of sight for Domination.

Torment can be highly deadly early on, so make sure to line up your Barrier with every torment set.

Make sure to look out for Decimator, so you don't end up falling down in a hole. Whenever you find yourself in a bad position or baiting a bad Decimator, alter time or blink can help you get back into position.

IMPORTANT: So, unlike Heroic and Normal, there will be a set 6 bombs in p1 instead of 3. Make sure to position correctly and react to the bomb you are assigned to. Make sure to position yourself properly if you are assigned to heal the boss with Surging Azerite.

World Shatterer can be deadly if you are not at full health, so keep an eye out.

Your damage will mainly depend on the powers that you gain from the anima orbs. Anything with crit, haste or any damage modifier will be beneficial for you as Frost Mage.

Make sure to save Blink for Hungring Mist to reach the safe spot as fast as possible.

If you are assigned to it, you can soak Chains of Eternity with Ice Block. Remember that we have 2 Ice Blocks thanks to Cold Snap, so don’t be afraid to use it.

Legendary: Slick Ice

For this boss, you want to use the single target build. Splitting Ice gains a lot of value since we have to deal with an add on top of the boss, so, Freezing winds legendary pulls a little ahead on this boss.

You will only use Icy Veins when the boss is active since his intermissions are at 66% and 33%. We want to ensure that we have as much uptime as possible to maximum our Icy Veins Duration.

If you are low on health during the intermission make sure to use Ice Barrier / Mirror Images because Titanic Death Gaze will deal a lot of raid wide damage and you don't want to be caught off guard.

The boss will also cast Annihilating Glare, which is a big beam that you can Blink through to get more uptime on the boss. You can also use Alter Time to get back to a safe spot and avoid the beam. Just keep in mind that this requires a bit of practice.

Mythic Mechanic - During the intermission, the raid will split into two groups. Make sure you are on the right side with your allies for Hopeless Lethargy so you don't blow up the raid.

You want to use your single target setup for this boss because we will be facing the main boss for quite some time. However, there is still value in using the Freezing Winds legendary because we have 2 targets up for some time.

You want to make sure to cast Blizzard on cooldown when the 2 bosses are up. You also want to save your Blink in case you need to soak Aradne's Falling Strike.

I suggest having Mirror Images or Ice Barrier up when you need to soak Arthura's Crushing Gaze with the rest of the raid.

Legendary: Freezing Winds

Make sure to have between one or two Fingers of Frost when the orbs spawn for maximum cleave damage.

Make sure to have Ice barrier ready for every shatter. You can even use Alter Time right before it happens and then alter back after to avoid some of the heavy raid-wide damage.

Make sure to save Blink or Alter Time for Malevolence. Alter Time is an easy way to get back to the platform after being knocked off by Malevolence.

Legendary: Freezing Winds

This boss is mainly a single target fight with occasional adds. However, they will have priority over the boss when they spawn, so you want to make sure to have Rune of Power and Frozen Orb ready.

Make sure to save Blink for Tormented Eruptions to reach the safe spot easily.

Don't use Ice Veins during Tormented Eruptions because we won't have good uptime on the boss.

Make sure to CC the Mawsworn Agonizer with Polymorph if you are assigned to it.

During Warmonger Shackles, you want to make sure to use Ice Barrier or Alter Time to heal yourself due to the heavy raid-wide damage.

Remember that you can die during Alter Time due to the high raid damage. I wouldn't recommend waiting until the end of the chains to Alter Time back.

Legendary: Freezing Winds

This boss is primarily a single-target fight, so you can choose to use the Slick Ice or Freezing Winds legendary. However, there will be a couple of adds spawning after each intermission. The boss transitions at 70% and 40%, so don't use Icy Veins when he is about to phase. You also want to make sure to have Icy Veins and Frozen Orb ready after the intermission because there will be multiple targets on top of the boss that you need to DPS.

When the spiked balls spawn, you want to make sure to use Blizzard on them to reduce the cooldown of Frozen Orb.

Remember that you have Ice Block available if you find yourself falling behind during Shadowsteel Chains.

Mythic Mechanic - After every intermission, there will be multiple adds that spawn.

Legendary: Freezing Winds or Slick Ice.

You want to make sure to have a healthy amount of HP for Purging Protocol. It's a good idea to use an Ice Barrier during the cast to reduce the damage.

Make sure to have Blink or Alter time ready when you get targeted by Threat Neutralization because you might be out of range of your healers. I would recommend you to use Alter time so you can alter back to full health and get back back to your position as fast as possible.

Make sure to have Ice Block available if you are assigned to soak Oblitirate to reduce the number of players soaking. Usually, this is countered with a couple of immunities, such as Ice Block.

Mythic Mechanic - Threat Neutralization must be placed on top of the energy cores (Requires Blink or Alter time).

Legendary: Slick Ice.

For this boss you want to use the single target talents because we will mostly be fighting Fatscribe. However, during the intermission you will have some adds that you need to cleave down unless you need to handle the rune mechanic.

Make sure to hard swap on the tank add to your apply slow, since the add needs to be kited.

You also want to make sure NOT to use Icy Veins when the boss transitions at 70% and 40%, even if the rune mechanic does not target you, so you don't waste any uptime on Icy Veins. 

Make sure to have Frozen Orb and Rune of Power ready when the tank add dies because it will spawn multiple small adds.

Mythic Mechanic - Grim Portent, make sure to have Blink ready to run and soak it quickly.

Legendary: Freezing Winds.

You want to use the single target talents for this boss because we will mostly be fighting Kel'thuzad. However, there will be multiple adds spawning and many downtimes since Kel'thuzad has to be phased in a specific time to not interfere with the rest of the abilities.

You want to have Blizzard, Frozen Orb, and Rune of Power ready for the add Waves.

Make sure to have Ice Block ready for frost blast in case you are assigned to soak it. Keep in mind that we have two ice blocks in our toolkit, which essentially gives us the option to soak two Frost Blasts if needed.

Make sure to interrupt the Soul Reaver.

Save Ice Barrier or Mirror Images for when a Glacial spike dies because heavy raid-wide damage will occur.

It is unlikely for a frost mage to go to the Phylactery Realm. However, if you are assigned, make sure to save Icy Veins for Remnant of Kel'thuzad.

Don't use Icy Veins during the Intermission. You want to save it for when Kel'thuzad appears again. Alternatively, you can use Rune of Power and Frozen Orb With Blizzard.

Wait for all the adds during the Intermission to be stacked before using Frozen Orb to maximize damage.

Legendary: Freezing Winds.

Mythic mechanics

During phase 1, you will have adds spawning from Black Arrow, so you want to pick Ring of Frost as your level 45 talent on this encounter.

During phase 2, your raid will be split into two groups, similar to heroic, just with more adds.

During phase 3, you will get an additional set of Death Knives and puddles on that ground that needs to be soaked, called Merciless.

Legendary: Freezing Winds.

Phase 1

You want to make sure to have high stacks of Chain Reaction for Domination Chains and try to use Frozen Orb on them as well. If you see that Domination Chains are about to happen and Frozen Orb is not ready, you can try to force the cooldown reduction by using Blizzard on Sylvanas.

Make sure to have Blink ready for Veil of Darkness.

During Black Arrow, heavy raid-wide damage is going on, so make sure to have Ice Barrier or health pots if you have any available.

After Black Arrow, multiple Sentinels will spawn, so make sure to cast Ring of Frost to keep them CC'ed because they are extremely deadly if they reach their target.

Remember that Sylvanas will transition at 84% health, so make sure NOT to use Icy Veins during the Intermission since there is a particular time that you want to do as much damage as possible.

Phase 2

During phase 2, you will be able to attack Sylvanas twice, so make sure to save your Icy Veins for that.

Phase 3

During phase 3, there will be constant heavy raid-wide damage, so make sure to have Ice Barrier up as much as possible.

Keep in mind that you can soak Merciless twice with our Ice block due to cold snap.

If you get targeted by Wailing Arrow, you can use Alter time to get back to the platform. Make sure to wait until the arrow lands and hits you because you don't want to drop Wailing Arrow on top of the raid.

There is a large amount of raid-wide damage during Banshee's Fury, so it's a good idea to use Alter time to heal yourself back to full health.

Legendary:

You want to use Slick Ice as your legendary.

Mechanically:

Alter Time > Shimmer out > drop pool > Alter Time back is a great way to handle Echolocation. If you get hit by Echoing Screech you can toggle Ice Block of the horrify effect and pretend like it never happened.

DPS increase:

1. To maximize DPS on this fight there are a couple of things we want to look out for as a frost mage.
   Like stated above we don't want to stop casting and losing DPS because we got targeted by Echolocation. Position yourself so that if you get targeted to have a plan to safely Alter Time > Shimmer out > drop the pool in a nice place away from group > Alter Time back, all this while still 100% maximizing DPS uptime.
2. There is an intermission on this boss from 1:54 - 2:30 at which point we can no longer hit the boss. This means that our 2nd usage of Icy Veins should be used around 1min, rather a few seconds before that than after, even if you could extend the first Icy Veins for a longer time, this is important to do so that we can ensure that we have our 3rd Icy Veins ready when he comes back at 2:30.

Legenday:

You want to use Freezing Winds as your legendary.

Mechanically:

You can use Polymorph to CC the Shades of Bargast adds until the raid is ready to kill them. On mythic you can help soak the Sinseekers from p2 and onwards with Ice Block, since the ability spawns a ghost that needs to be healed with lower HP if you took a bigger hit, since you don't take damage while in Ice Block you spawn a ghost that is easily healed by your healers.

DPS increase:

Keep Blizzard up if the boss and a dog is stacked. This is really a fight where Splitting Ice + Freezing Winds can shine. To maximize damage you need the tanks to keep as much of the fight in stacked cleave(dog on top of boss) this isn't doable to do at 100%, but the longer the better.

Legendary:

You want to use Freezing Winds as your legendary.

Mechanically:

There isn't much you can do as a mage on this fight, at most you can help slow the adds such as the Soul Infusers.

DPS increase:

DPS on this fight doesn't really matter, what I mean by that is that this is a very DPS pad fight. Yes the adds needs to die but most of the time your raid has more than enough damage to handle them. That is why I like to use the legendary Freezing Winds. This means you will have good burst for shields in the intermission on the Shade of Kael’thas, just make sure you have a Frozen Orb ready for it, and still to a lot of overall damage here. You can Blizzard on the phoenixes in the intermissions if your group isn't hard CCing them, this can get you some faster Frozen Orbs off cooldown.

Legendary:

You want to use Slick Ice as your legendary.

Mechanically:

Mage have more than enough movement to handle the Seeds (talking mostly the mythic seeds), there are multiple different ways you can handle them. I like to Alter Time at the boss > move to seed with Shimmer / Door of Shadows / Soulshape pick it up, then use movement again to get the Seed to the other side, whether that its with the help of Dimensional Tear or not, drop the seed in a safe location, then Alter Time back. But if you like to handle it some other way, feel free to do so. Don't fix what ain't broke.

You can use Ice Block to tank the Fleeting spirit so that you don't get mind controlled, or if you failed that you can still use Ice Block to remove the mind control. You can also use Ice Block to remove Withering Touch which does a lot of damage on mythic, but I would rather save Ice Block for spirits. If you get Withering Touch on you this is a great place to use Mirror Image to reduce the damage and help your healers.

This fight is mostly about getting the Seeds to a safe place so that the raid can live, this is where mages shine, so good luck.

DPS increase:

This fight can be so on and off, if you get targeted to place the Dimensional Tear at the wrong times, there isn't much you can do. Same with Ghosts and if you are handling Seeds. But there are a couple of things we can do to try and avoid the really bad stuff. So like I said before, if you are not a Seed carrier using Ice Block to soak the ghosts(Fleeting spirit) is a great way to minimize the damage loss of that ability. If you are a Seed mover there are movement things you can do to maximize damage, HOWEVER I can not understate this enough, do not let your damage mind make you fail to the get Seed to a safe location. That is not worth it. If you see Seeds coming up but you are soon getting ready to pop Icy Veins, although holding Icy Veins is generally pretty bad, in this case its worth to first handle the Seed and then pop CDs so that you get a better use of the Icy Veins.

Legendary:

You want to use Slick Ice as your legendary.

Mechanically:

Alter Time is great for when you are targeted by Gluttonous Miasma, especially if its combined with one other boss mechanic such as Volatile Ejection, Expunge or Desolate. Even if you can't be healed you can still “go back in time” to your old higher HP value. During Gluttonous Miasma you can also get shielded, so save your Ice Barrier for times when you need it, there is not reason to press your shield when you have other players soaking you(healing you). They are still gaining stacks for soaking and you are wasting your shield.
When you soak another players Gluttonous Miasma you gain Essence Sap, which increases the damage you take from soaking, this debuff can be removed with Ice Block, so if you need to help soak but you are already at high stacks, toggle block to remove the debuff. Frost is great for this since you can use Cold Snap and have Ice Block again.

DPS increase:

Not much to say really, this is a pure single target fight. With some mechanics that force you to move at certain points. To maximize damage you need to try and still have as high uptime as possible while still doing mechanics. This includes using Shimmers to deal with Expunge or to get into position with Gluttonous Miasma and so on. Try to utilize the movement when you are doing Shatter combos, for example during a Brain Freeze proc you can move for 3 globals, the Flurry and 2x Ice Lances. High uptime = High DPS.

Legendary:

You want to use Freezing Winds as your legendary.

Mechanically:

The soaks from Bottled Anima spawn relatively close to players, this means that if your raid is somewhat stacked you will get closer soak spawns. But keep an eye out for soaks that no one is going for, you have great mobility as a mage and you can use Shimmer to help your raid.

The adds that spawn come from a cast called Concentrated Anima, if you were to be targeted by this ability while inside of Ice Block your “immune” the add debuff and will therefore not spawn an add. This can be a great resource making your raid not have to deal with the adds if enough people can immune certain harder waves.

DPS increase:

The adds spawn generally in intervals of around 1 minute starting at the one min mark. There are situations where they can be skipped and where they spawn closer together towards the mid-end portion of the fight. You want to make sure you have a Frozen Orb for every add set to get the value of cleaving your Fingers of Frost Ice Lances. There might be situations where you can get an orb in between add sets while still getting good value on the adds with orbs, but this is something you have to figure out with your raids DPS.

Legendary:

You want to use Freezing Winds as your legendary.

Mechanically:

There isn't much you can do here that is specific to a mage, you try to handle mechanics like everyone else. You have pretty good damage on the Dutiful Attendants with Brain Freeze procs, but don't hold them to kill the adds.

DPS increase:

Although the damage profile of this fight is generally single target, since there are often more than 1 target that can be damage but where the damage is irrelevant its still very worth to Blizzard on-top of the bosses to gain the value of lower cooldown of Frozen Orb. This is why the legendary effect Freezing Winds gains so much value on this fight, more orbs means higher value for the legendary.

Legendary:

You want to use Slick Ice as your legendary.

Mechanically:

This fight doesn't invite grand movement portions, which you would think makes mage not the best mechanically fit for this fight, however mages are very tanky and have an ability called Alter Time that gains great value on a fight like this. After every pillar Sludgefist will do a Colossal Roar, we use this knowledge to remove the damage inflicted. Meaning, during the pillar phase when you are on high % hp you press Alter Time, waiting for the roar to come out after the pillar and then you Alter Time back to your high hp%. This is a portion of the fight where you are never linked with another player through Chain Link so you don't have to worry about that.

DPS increase:

This fight unfortunately invites high burst specs which frost is not. If you can go fire or arcane here I would recommend that to be fair. However if you want to play frost there are a couple of things we wanna do. If you play ventyr you need to know that Mirrors of Torment needs the boss to be active to function, so we do not get value from it during pillars. So that means make sure you use it outside of pillars, start with using it on pull and go from there. The pillars happen a little of every 1 minute, so we will have Frozen Orb during each one, with the first one happening around 57 seconds in we will get during the pillar. Try to have Rune of Power either from Icy Veins or the casted one up during the pillars so that we get double the value from it.

Legendary:

You want to use Glacial Fragments on Mythic and Freezing Winds on Normal and Heroic difficulty.

Mechanically:

Per usual with us mages having great movement capabilities we are often tasked with soaking and this fight is not any different, we are also kinda tanky and that works great for Reverberation Eruption. If there are soaks during a portion of the fight where healing is reduced from the goliaths ability Soultaint Effigy a great way to stay safe is to use Alter Time before the damage > soak, take damage > Alter Timing back to your high HP% much like on Hungering Destroyer. The damage from these soak DOES damage through Ice Block which lessens the value of Ice Block for this fight, but we can still use it to remove Heart Rend without gaining Heart Hemorrhage, or to remove the stun from Pulverizing Meteor.

You cannot use Ice Block to remove Serrated Tear or to never gain it.

DPS increase:

On this fight we are an absolute add killing machine. If there are only the boss and the Goliath or 2 bosses at the end we play as normal even with the legendary Glacial Fragments, but as soon as there is 1 more add in there we start just using Ice Lances, but make sure that the adds are in Blizzard while doing so, this is only for mythic. If you enter intermission while still having Icy Veins up we need to keep casting spells to further increase Icy Veins uptime and to reduce the cooldown of the next Icy Veins. If you are not supposed to do damage to the Goliath or the Commandos (mythic) even if there is no real value to DPS the almost immune to damage boss we need to do so to keep the Icy Veins flowing.

Legendary:

You want to use Freezing Winds as your legendary.

Mechanically:

Blood Price throws you up and deals a lot of damage, you would think Alter Time would be perfect for this, but unfortunately it doesn't work for this mechanic. However we can still utilize it for other stuff such as the knockbacks from Shattering Pain in phase 3 or the pull from Hand of Destruction. Alter Time can also be used to mitigate damage from Impales and so on.

In phase 3 when you get targeted by Fatal Finesse, after you have dropped the “seed” off you gain a damage taking debuff, this debuff can be removed by Ice Block, this debuff also stack, so if you for some reason have more than one, you can use Ice Block to help your healers. In Ice Block you do not get hit by Masacre, or knocked from Shattering Pain. This is especially useful during a hard overlap in phase 3 of mythic Sire Denatrius.

DPS increase:

There isn't much to say about P1 or P3 of this fight honestly, however P2 is where a frost mage in the right place will do a lot of damage, especially if you get to go to the right adds on mythic. This will mostly be about mythic Sire, but if you are frost on mythic Sire in p2 you want to be able to follow to boss to the adds, generally these are Evershade and Duskhollow, so that you can utilize your good cleave. Your Frozen Orb will fall in-between the platforms here so to get the orb onto the adds you need to get to the add platform, if you get to do Evershade and Duskhollow normally that is Evershade gateway(warlock gateway) and you just cast a spell onto Duskhollow to fly over there. If you want to do good damage as a frost mage on this fight is all about maximizing the cleave damage in phase 2.