For reference here is the ring:
First, a few assumptions.
1) The legendary ring explosion impacts Prismatic Crystal. From everything I've read, this is a safe assumption.
2) All damage sources contribute to the legendary rings final damage for the duration of it's charging period.
3) Prismatic Crystal damage amplification may or may not effect the ring explosion itself, but does effect the spells that can build the rings explosion value.
From these assumptions, which I think are fair to make, one can surmise that in 6.2 there will be a strong emphasis placed on two types of damage:
1) Controllable, semi-frequently available, high magnitude burst damage
2) Sustained AoE
The first of those damage sources is for single target encounters. Controllable is obvious - you have to be able to choose when to burst to best take advantage of the 15s window you have to dump damage into the ring. Semi-frequent is an additional trait that is desirable. The ring CD is currently 2minutes. Having your primary burst be centered around 3min+ CDs means that you cannot have your burst available for every ring CD, and so you are under-utilizing the effect. High magnitude is also obvious. You want to dump a huge amount of damage into the ring so that you are maximizing the effects.
If we look at our specs, Arcane and Frost immediately come to mind as candidates for controllable burst. Arcane, with it's burn phase, Arcane Power, and Evocation being completely under its control can easily swap into a damage dump phase to power the ring. Frost can utilize Frozen Orb and Ivy Veins in a similar manner, in addition to proc banking, to ensure that it is able to dump a large amount of damage into the target when the ring proc is up. Fire, while capable of a large amount of burst in combustion, does not always have this burst available as it is reliant on a good combustion set up to pull off and with the loss of the 2xIB trick this will be less easy to ensure.
Arcane and Frost are our best candidates so far for single target. However, they don't pair up equally in regards to the next two desirable traits. Frost has Frozen Orb every minute, but the throughput from this is significantly lower without Icy Veins. Icy Veins, being a 3min CD, will not be available for every ring CD and is therefore not as desirable. Arcane on the other hand has the option of leaving Arcane Power unglyphed, lasting a convenient 15 seconds, thereby giving Arcane the ability to have controlled burst for every ring CD.
There is the possibility that the throughput of Frozen Orb + Icy Veins every other ring CD is still competitive with Arcane with it's Arcane Power every ring CD, if the damage from Frozen Orb + Icy Veins is significantly higher than the damage we would gain from Arcane Power. So, let's look at the burst in two very simple ways.
Simulation based comparisons (using 6.2 PTR data):
Arcane
Frost
Napkin Math based comparisons:
For both of Arcane and Frost I'm going to assume no haste.
Arcane
For Arcane specially I'm going to begin with the assumption that we're at 4xArcane Charges when the ring begins pooling damage done. Additionally, I'll assume that the current T18 2pc set bonus (Each time you cast Arcane Blast, the cooldown of your Presence of Mind is reduced by 30 sec) is available and that the pets summoned by the 4pc don't deal damage that contributes to the ring. This second assumption is mainly because I don't know what the pets do yet. I'm also going to assume that we're just spamming Arcane Blast into the ring. Arcane Power is up, and just to make things interesting we're going to assume that the class trinket is being used!
Under these assumptions (and some other details like certain amounts of different stats), Arcane is going to deal ~879k mil damage into the ring to be modified and turned into the explosion.
Frost
For Frost I'll assume the same stats as Arcane (just with less mastery / more multistrike). I'll assume all FoF-ILs and FFB-BFs are critical strikes, that the T18 2pc is a +40% damage modifier onto BFs existing damage modifier, and that you have 5 icicles stored from frostbolt spam from before the ring begins storing damage. We get 10 ticks of FO, and cast 2xBF-FFBs followed by 6x FoF-ILs (5 of which get Splitting Ice treatment, since we drop PC in there to).
Under these conditions, Frost deals ~868k damage into the ring.
If you want to look at exactly what I did, it's here: https://docs.google.com/spreadsheets/d/ ... edit#gid=0" target="_blank
There are a couple things I think we can take away from this.
If we just look at the sims (which honestly are extremely rough estimates - the arcane profile isn't even using the AP trinket), we see the problem I brought up earlier. Arcane has consistent burst at the 1.5min interval, which can be sync'd with the ring (and enhanced further with the trinket). Frost on the other hand has significant burst potential - but it's only every 3 minutes. So timing is definitely a major issue for Frost - it relies very heavily on Icy Veins to generate burst.
If we use napkin math, we see that with the AP trinket involved Arcane burst actually starts to equal Frosts burst potential (I reduced the Arcane spell power amount due to the use of the arcane trinket, just to be clear). But for Frost, there is no way to provide a significant spike to burst. Because the Arcane trinket is currently simming as a significant DPS gain overall, this gain in burst potential isn't coming as any tradeoff either - it's just a straight up DPS increase which also allows Arcane to sync significantly better with the ring. On top of this, if the ring is actually affected by the PC amp value (which it very well may be), Arcane is by default the winner here as well since its PC amp value is 30% vs the 10% of Frost.
Moving onto the second type of damage that will be favored, sustained AoE. I say sustained AoE because the ring says it deals 25% of "all damage they dealt." To me, this means to ALL targets. Meaning, if I have 10 pyro DoTs, and 10LB DoTs rolling/exploding, and 10 ignites ticking, ALL of that damage goes into the ring. I don't think I need to run sims here or do any sort of math to say that for 2+ targets, Fire is going to dominate this sort of damage type.
Putting all of this together, the ring seems to be undermining the efforts put forward to bring Frost up into a more competitive realm in 6.2. It takes the problem of Arcane > Frost on ST and exaggerates it further by providing another mechanism that Arcane mages can abuse harder, and more often, than Frost mages. In the realm of AoE, Frost never had a chance against Fire to begin with and none of the tuning changes really bolster Frost AoE in any significant way to change that. With so much emphasis people are placing on the ring (which could be misguided, to be fair) I don't see a reason to play Frost in raids next tier if the current ring design stays in place and has the kind of impact on DPS people are anticipating.
