This 'only' part can easily be taken out of context. It's important we note just how much damage is done during that ~55 sec ground phase, compared to an entire ~4 minute air phase. From my logs, for example: Having gained 25 stacks as fast as possible during the air phase, I still did ~twice as much total damage during the ground phase. (Boss damage only, ignoring impact on adds)

So I'm not the only one to notice this. We were doing Halfus hc on Tuesday, so I went fire for this (arcane is my normal spec nowadays). I could not get impact to work at all during the fight which was really disappointing. After the raid, and again last night, I went to the Org dummies to run some tests. Where before impact would spread living bomb every time, now it was working rarely. Are we the only two to notice this ?

You're not the only one, it happened alot lately and I had users of CombustionHelper reporting it too, believing it was coming from my addon, which is obviously not the case. Strangely this haven't been brought up more than that.

I can confirm Impact's odd (mis)behavior.

As others have reported this bug is related to the recent Impact spreading change that allows Living Bomb to remain on the most recent target, and simply fails to spread it to the two additional targets.

This bug, until fixed, creates a seemingly random factor that will negatively affect your potential DPS. I was unable to reproduce it reliably - Indeed upon first encountering it my initial impression was that the mobs were somehow out of range. Cannot give any numbers on how often it happens given my small sample size. Needless to say when it did happen it was noticeably annoying.

I believe some time ago, it was confirmed that the target dummy's were not great places to check Impact on. It's the same thing that makes testing Frost specs on them terrible, they are NOT immune to being frozen, so Deep Freeze hits them, they freeze. At the same time they can't be stunned(part of Impact), so the spreading part doesn't happen. I had a ticket dismissed by a GM when I reported Impact not spreading DoT's on target dummy's. The response was akin to, were sorry, but the dummy's are not able to replicate every ability correctly, and are there as a "convenience".

Isn't that counterintuitive? If they CAN be deep freezes then they CAN be stunned, which means impact stun should work. Does impact even have a visible effect for you to know if the target was stunned or not?

I did not have Chalice for those logs. Chalice, Firehawk Legs, and Heroic Volcanospike are all new equipment on my character's armory that were not present when the logs that I posted were taken. At the time of the WoL parse I was wearing a DMC:V, normal Firehawk legs, and normal Volcanospike.

For Mastery calculations, I went by the literal description from our Talent sheet:

"Increases the damage done by all your periodic fire damage effects by 22%. Each point of Mastery increases periodic damage done by an additional 2.8%."

I computed my (effective) Mastery Rating using my character's stats with the gear I had equipped and the averaged mastery gain from the heroic Theralion's Mirror trinket. This worked out to be 17.595 Mastery. 17.595 Mastery multiplied by the "additional 2.8%" from the talent description produces 49.3%. Since this is "additional", I added that 49.3% to the base "Increases the damage done by all your periodic fire damage effects by 22%", which ends up as a total of 71.3% bonus to periodic fire damage.

That being said, even if I was wrong and double-counted the baseline mastery, it means that my logs are actually showing 22% more damage than it should be.

I just tested this at the raid-dummy in SW and DF did damage. Seems to have been fixed.

When considering trinkets for flying fire mages during the Alysrazor encounter, can anyone give me some input on the availability of Theralion's Mirror proc during Burnout? I was thinking if I'd rather risk not having it proc during Burnout (and missing out on a lot of Combustion damage) and instead getting a guaranteed 420 mastery from Necromantic Focus; but couldn't really come to any meaningful conclusion.

For Fire Heroic Alys -

I have found that creating a heavy mastery orientated set to be highly successful. Mixed with the 4 piece your ignite and combustion will easily become your #1/#2 sources of damage for this fight.

Pre-Rune of Zeth, i was using Necromantic Focus + Volcano Card(Unreforged). Not dpsing Alys during the Tornado phase allows your icds to come back up and then you can combine them all on the expose phase for 350-400k single target combustion peaks.(Obviously more if you can impact to the adds unnecessarily).

Note: You can make the "argument" to your unwilling tanks that you want to get up Pyromaniac - But if you have 25 stacks, 5/10% more haste is wasted and not useful, and the adds aren't there when your buff runs out.

If you are solo flying, just before the alys firestorm you can delay picking up the last ring Alys spawns, grab it, and iceblock the 5 seconds she channels up the air, and grab a new ring when she flies around again - This is a 1-2 second window and not recommended with someone else grabbing rings.

Speccing out of blast wave and imp flamestrike gives you Molten shields and 1/2(or2/2) blazing speed gives you more mobility for grabbing rings during ground phase - i.e if your blink is down you can force proc your BS to quickly reach a ring to refresh, which translates into an enormous dps gain.

Additionally(since i dont have much xp with normal), i have found that wings of flame isnt refreshed correctly on heroic with a feather post firestorm - which means i run a simple cancel aura for it and grab new one and dont need to deal with the buff not working correctly.

Glyphing Pyro instead of LB is also a strong decision, with 4 piece you are a crit factory and will see significant uptime of enormous ignites.

Combustion timing seems to work out as follows - Combustion on pull with a prepot ignite - Combustion again post first Firestorm - Combustion expose phase - Combustion pre 4th firestorm - Save combustion for next expose - Combustion pre 6th(if you have it) etc...

Don't forget about those Flame Caps :P