Fire Mage playstyle and rotation guide

Combustion Rotation

Precast Pyroblast.

If Pyroblast doesn't crit do the following:

1. Fireball
2. Combustion while halfway through casting fireball
3. Fire Blast
4. Fire Blast
5. Pyroblast
6. Pyroblast
7. Phoenix Flames
8. Pyroblast
9. Fire Blast
10. Pyroblast
11. Phoenix Flames
12. Pyroblast
13. Fire Blast
14. Pyroblast
15. Phoenix Flames
16. Pyroblast
17. Fire Blast
18. Pyroblast
19. If you have more time left on Combustion, then you want to cast Scorch into Pyroblast, if you are a troll this is possible with blood lust + berserking. If you are an orc, this is possible with Bloodlust + Power infusion.
20. If there is some time left and you feel like you wont be able to fit another spell in the Combustion window use Dragon's Breath.

If Pyroblast crits, do the following:

1. Fireball
2. Combustion
3. Fire Blast
4. Pyroblast
5. Fire Blast
6. Pyroblast
7. Phoenix Flames
8. Pyroblast
9. Fire Blast
10. Pyroblast
11. Phoenix Flames
12. Pyroblast
13. Fire Blast
14. Pyroblast
15. Phoenix Flames
16. Pyroblast

Outside of Combustion Rotation

When outside of Combustion your rotation is the following:

1. Rune of Power
2. Fireball until you get a heating up proc
3. Fire Blast
4. Pyroblast

Use Rune of power and Shifting Power right after Combustion, remember to prevent overcapping fireblast charges.

Combustion Rotation for Mythic+ or 4+ targets

1. Flamestrike (hardcast)
2. Combustion during flamestrike hardast
3. Fireblast
4. Fireblast
5. Flamestrike
6. Phoenix Flames
7. Fire Blast
8. Flamestrike 
9. Shifting Power
10. Fireblast
11. Fireblast
12. Flamestrike
13. Phoenix Flames
14. Fire Blast
15. Flamestrike
16. Fill up the remaining duration of Combustion with a combination of Scorch and Fire Blast into Flamestrike.

Playstyle

Keep casting fireball, you can use shimmer to blink during fireball casts as well. It is extremely important you maximize uptime on fireball casts to ensure that you have 1 minute combustions.

Make sure you enter Combustion with 3 Fire Blast and Phoenix Flames charges.

When your target is below 30% health, you want to cast Scorch due to the talent Searing Touch to generate Heating Up procs.

On 2 or more targets, if no priority damage is required, you hard cast Flamestrike with Flame Patch. Keep in mind this depends on the situation, huntsman for example is mostly 2 target, but because the 2nd dog keeps getting dragged it’s not worth it at all. Also this means combustion cooldown is not 1 minute.

Make use of your many defensive abilities like Blazing Barrier, Alter Time, Mirror Image and Ice Block to stay alive.

Playstyle with Sun King’s Blessing

Sun King’s Blessing: After consuming 8 Hot Streaks, your next non-instant Pyroblast cast within 15 seconds will grant you Combustion for 6 seconds.

Because of how Sun King’s Blessing works it will change your rotation and priority list, so I will try to break it down to make it easier to understand.

Our main goal is to extend Infernal Cascade and use as many globals as possible during our big Combustion and during our 6 second Sun King’s Blessing window.

This legendary especially shines during execute with Searing Touch. You will gain Combustion pretty much every 10 seconds if you use Scorch, which essentially gives us a massive spike of damage.

Night Fae

As Night Fae, you want to activate Shadowed Orb of Torment at 5 Seconds and then proceed with your regular opener as mentioned above.

You will perform your regular combustion rotation. However, there are a few things to keep in mind.

After Combustion is over, you should have 7 stacks of Sun King's Blessing. If you have the stacks, you then want to use Shifting Power, Rune of Power, and hard cast Pyroblast in order to activate the buff of Sun King's Blessing. When you have the buff, you want to use your remaining fire blast and Phoenix Flames from Shifting Power.

You want to line up the Pyroclasm procs with Sun King's Blessing to get a big crit. Other than that, do not over cap on Pyroclasm procs, and remember that you can bank up 2 charges of Pyroclasm.

Venthyr

Remember that you will get a ton of Fireblast refunds with Mirrors of Torment, which gives you the option to be way more aggressive with your Fireblast charges during Combustion and Sun King's Blessing. You also want to keep in mind that you will proc Sun King's Blessing after every combustion if you have a good amount of Fireblast and Phoenix Flame charges because to proc the buff you need 8 hot streaks in a row. If you combust with a low amount of charges, you might not get the buff.

Another thing you want to remember is to save Mirrors of Torment for Combustion because you want to line it up with Shadowed Orb of Torment; unless the boss is about to die, then you want to use it whenever it is available.

Unfortunately, as a Venthyr mage, we don't have access to Shifting Power, which means you have to use Scorch during your Sun King's Blessing to extend Infernal Crusade, which is your number 1 priority during every single Combustion.