Hey guys, I've never posted anything on mmo-champion but I decided to post this to help out the community.
When I was progressing on Heroic Garrosh, I could not find a single 10m Heroic Garrosh "Fire" Mage POV video.
Only arcane PoVs.
If you play fire spec properly, you can pull higher dps than arcane.
Here's my Youtube vid
Some tips for Heroic Garrosh as a Fire Mage
1) NEVER use Inferno Blast when people are mind controlled [assuming they're near the boss]. If you use inferno blast, you will spread your dots [pyroblast/ignite/combustion] and they will still take those dot damage even after they come out of mind control. Be very very careful, I've accidentally spread my combustion in phase 3, and killed my raid member in 2 seconds after they came out of MC.
2) Before you go into the 1st transition phase, have both pyroblast! and heating up! proc up to burst down the adds. This isn't normal. Heroic transition phase adds have much higher HP than normal adds. Fire probably has the weakest burst out of all 3 specs, but if you have both pyroblast and heating up proc before going into the 1st transition phase, you should be fine.
3) Always use your combustion with at least one trinket is active. When your trinket[s] proc, your int will be very high for 10~20s which means higher chance and higher crit. Your ignite dot will be much higher, so your combustion dmg will be much higher. As you can see in the video, my combustion was always used when immerseus trinket was procced.
4) DO NOT attack the boss during the roleplay of Phase 3. You do not want your trinkets to proc going into phase 4. There's about 20s Roleplay between phase 3 and phase 4. In my video, I failed to do this and my Immerseus trinket was on CD at the start of phase 4.
My roll in my raid was just to sit behind boss and dps. I could've done this fight pretty well as arcane but didn't feel like playing a boring spec for a month on Garrosh [sorry if I offended any arcane players]. Also, Fire is much better in phase 4, when you have to run from end to end.
Correct me if I'm wrong but frost is far behind fire/arcane in this fight.
Hope this helps! and
Happy Holidays