It is hardly a secret that Shadowpriests have been avoiding Power Word: Insanity like the plague; an ability that consumes your Shadow Word:Pain in return for a modest amount of damage (and only if consumed at the very last moment) is like trying to play whack-a-mole with a set of tweezers. Now Blizzard noticed this and tries to put the plague back into this talent, redesigning it for patch 5.2.
The current incarnation of the ability as presented is “Solace and Insanity”. We ignore Solace – that’s for our healing brethren. The “Insanity” portion basically causes your Mind Flay to deal double damage while there are three shadow damage DoT’s on the target. This wording is very important because it’s the difference between Insanity being total suck or total win.
When you think of the reasonable application, it means that Mind Flay deals double damage only with three of your shadow damage over time effects. That would be all three of VT, SW:Pain and DP. And considering that DP can be applied with 1 to 3 Shadow Orbs (increasing its damage) it suddenly becomes a pain game of deciding whether a 2-Orb DP + double damage MF more often is worth it over a 3-Orb DP with less double damage Mind Flays. In practice, it won’t be.
Taking an 8 second cooldown, you will have a 3-Orb Devouring Plague every 24 seconds, after which your Mind Flay (3 second channel base) will deal double damage. Of course you might get lucky with the Divine Insight procs, but we should discount this for now to get the base value of the talent. This “bare increase” will give Mind Flay a slight boost in DPECT (Damage per Effective Cast Time). Basically, it’s DPECT value increases by 100% but only 1/10 of the time.
To get to this 3-Orb Devouring Plague we need:
- Three Mind Blasts (1.5 second cast time)
- Three Mind Blast cooldowns (8 seconds each)
- Devouring Plague (Instant cast + GCD)
- We can start casting Mind Flay
Total time required: 4.5 seconds casttime, 24 seconds cooldown, 0.5 seconds GCD = 29 seconds (let’s round to 30); Devouring Plague lasts 6 seconds base, giving us room for 2 Mind Flay casts. This gives us an active time of 12 seconds per minute; 20% uptime on the buffed Mind Flay. This also means a 20% increase (roughly) of the Mind Flay damage you’d see in your logs.
In the red corner, replacing our retarded Shadowfiend: Mindbender. With a minute cooldown base, the Mindbender is fire and forget, deals more damage and restores more mana than the Shadowfiend. It deals about 60% of the damage of a normal Shadowfiend, but can be used three times as often. You will see your “Shadowfiend related damage” increased by 80% if you have the Mindbender talent.
The key here is: which one’s higher?
If we read the tooltip literally
Well, we’d be happy with all our Warlock and Shadowpriest colleagues in the raid, that’s what. If we read it literally, it doesn’t say that we need 3 of our own shadow DoTs on the target, meaning we get the buff as long as aside of our main DoTs (VT, SW:P – which we should keep on our target at all times) one other Dotter is doing his job.
Corruption, Shadowflame, Unstable Affliction, Doom, and Shadowpriest DoTs will all count, and we can effectively say that in a 25man raid we have a 100% uptime on Insanity. That quite changes the outcome of things.
I am going to take the damage per cast time for Shadowfiend and Mindbender, and bring them back to damage per minute (the shortest cooldown), then I can see the benefit that Mindbender gives as opposed to having a vanilla Shadowfiend over a similar span of time. I don’t need to do that for Mind Flay, because it has a convenient channel time I can abuse for this. Here I can simply check the direct increase in damage based on its uptime of roughly 20%. (so also 20% more DPECT).
Shadowfiend DPECT (my gear):51529 (3 minutes cooldown) = 17.176,3 per minute
Mindbender DPECT (my gear): 36.129 per minute
Benefit of Mindbender vs Shadowfiend = 18.952,7
Mind Flay DPECT (my gear): 38.969 (3 second channel)
Insanity DPECT increase: 100%
Active time: 12 seconds/minute (20%)
Benefit of Insanity vs vanilla Mind Flay = 15.587,6
If all DoTs are counted, then the uptime of Insanity becomes about 10o%, massively improving the output of Mind Flay.
Mind Flay DPECT (my gear): 38.969
Insanity DPECT increase: 100%
Active time: 100%
Benefit of Insanity with all DoTs = 77.938 (!)
We can tell that if Insanity is triggered only by our own DoTs, it suffers from giving us a smaller increase in damage even if we’d time our Mind Flays perfectly, and on a Patchwerk style fight. With increasing Haste, the value of Insanity will slowly creep up to the value of Mindbender, but as soon as we have to move or suffer from lag, its value drops significantly. Also note that the 20% active time is really generous, considering it’s 6 seconds of buff for 29 seconds of rampup. Over a fight of 10 minutes you will have 34 buffed Mind Flays (so closer to 17%).
Only when it counts for all Shadow DoTs, from all other raid members, does Insanity catch up – and then it shines. Of course I did count 100% uptime here, but I think that’s reasonable considering that it takes only two Shadowpriests or Warlocks to get this done.
Do note that Mastery, which increases our Shadow DoT damage (and thus Mind Flay) scales very well with this talent. While Mind Bender doesn’t benefit from Mastery at all, a Mastery-heavy gear set will not only bump up DoT damage a lot more, but when combined with Insanity will also interact with the 100% damage buff. A +10% damage from Mastery effectively doubles while Insanity lasts and with a 17% uptime this will work out to 11,7% in practice (or +20% if all DoTs count).
I am not sure which design Blizzard is going to take, but if my napkin math hits anywhere near home, this choice will determine whether we will ever use the talent or not.