Single Target Leveling Rotation
Always keep your single-target Thunder on the target and only refresh it when it is about to fall off (less than three seconds), unless the target will die soon. This means that while you get a new Thunderhead buff each transition between Astral Fire and Umbral Ice, you will often end up ignoring/overwriting the buff until it is time to refresh the DoT.
Sub Level 35
Fire spam until low MP > Transpose > Blizzard until max MP > Transpose > repeat
Levels 35-59
Fire III and Blizzard III give you maximum stacks of their respective elements and replace the need to use Transpose to swap between Astral Fire and Umbral Ice.
Blizzard III > Blizzard > Fire III > Fire spam until low MP > repeat
Use your Firestarter procs as you get them, but don’t cancel or delay casts to do so. At 58+, replace Blizzard with Blizzard IV.
Umbral Soul should be used during downtime when you do not have a target to get back to full MP, Umbral Ice III, and at level 58+ attain three Umbral Hearts.
Levels 60-71
At level 60, Fire IV becomes the main MP spender in Astral Fire, but does not refresh the Astral Firer timer. As a result, in the middle of Fire IV spam a Fire cast is necessary to refresh the timer.
Blizzard III > Blizzard IV -> Fire III -> Fire IV x3 -> Fire -> Fire IV x3 > repeat
At 70-79, use Foul whenever. It does not have a set place in the rotation, is not affected by Astral Fire/Umbral Ice, and can often just be used in Umbral Ice so it does not make the Astral Fire timer tighter, but should be used/not let overcap as it is a strong spell.
If the Fire cast results in a Firestarter proc, it should be used in Astral Fire primarily for movement/weaving/refreshing the Astral Firer timer, but should be used even if not necessary for any of these.
Levels 72-89
Blizzard III > Blizzard IV > Fire III > Fire IV x3 > Fire > Fire IV x3 > Despair > repeat
Foul should be used similarly as before, replaced by Xenoglossy in single-target at level 80+. Xenoglossy provides additional utility since it is instant-cast and can also be used for movement/weaving as needed, as well as improved single-target damage over Foul.
If the Fire cast results in a Firestarter proc, it should be used in Astral Fire primarily for movement/weaving/refreshing the Astral Firer timer, but should be used even if not necessary for any of these. At 80+, consider saving the Firestarter proc through Umbral Ice, using Xenoglossy to weave a Transpose back to Astral Fire, then using the proc for a stronger reentry into your Astral Fire phase.
Level 90-99
Blizzard III > Blizzard IV -> Paradox -> Fire III > Fire IV x4 > Paradox > Fire IV x2 > Despair > repeat
Paradox automatically replaces Fire and Blizzard on your hotbars when entering Astral Fire from Umbral Ice III with three Umbral hearts, as well as entering Umbral Ice from Astral Fire III which will happen naturally with the rotation. Note that if opening a fight with Blizzard III, the initial listed Paradox in Umbral Ice will not be available.
Since Paradox is instant-cast, it is recommended to use four Fire IV casts before the Paradox in Astral Fire to allow for maximum leeway on the Astral Fire timer.
Your Firestarter proc should be used in Astral Fire primarily for movement/weaving/refreshing the Astral Firer timer, but should be used even if not necessary for any of these. Consider saving the Firestarter proc through Umbral Ice, using Paradox to weave a Transpose back to Astral Fire, then using the proc for a stronger reentry into your Astral Fire phase.
Level 100
Blizzard III > Blizzard IV -> Paradox -> Fire III > Fire IV x4 > Paradox > Fire IV x2 > Despair > Flare Star > repeat
Upon execution of all six Fire IV casts in a single Astral Fire phase, the Astral Gauge fills up and allows for the use of Flare Star. Since Flare Star does not cost any MP, does not refresh the Astral Fire timer, and Astral Soul stacks are lost upon exiting Astral Fire, it is recommended to cast Flare Star after the Despair.
Note that if opening a fight with Blizzard III, the initial listed Paradox in Umbral Ice will not be available.
Your Firestarter proc should be used in Astral Fire primarily for movement/weaving/refreshing the Astral Firer timer, but should be used even if not necessary for any of these. Consider saving the Firestarter proc through Umbral Ice, using Paradox to weave a Transpose back to Astral Fire, then using the proc for a stronger reentry into your Astral Fire phase.
See the main guide for further details and recommendations on playing the job at level 100.
AoE Leveling Rotation (3+ targets)
Always keep your AoE Thunder on the target and only refresh it when it is about to fall off (less than three seconds), unless the target will die soon. This means that while you get a new Thunderhead buff each transition between Astral Fire and Umbral Ice, you will often end up ignoring/overwriting the buff until it is time to refresh the DoT.
Levels 12-34
Blizzard II until full MP > Transpose > Fire II x3 > Transpose > repeat
Levels 35-40
Fire II and Blizzard II give you maximum stacks of their respective elements and replace the need to use Transpose to swap between Astral Fire and Umbral Ice. Use Umbral Soul during downtime when you have nothing to hit to get MP back.
Blizzard II x2 > Fire II x4 > repeat
Levels 40-49
Blizzard II > Freeze > Fire II x 4 > repeat
Levels 50-57
Blizzard II > Freeze > Fire II x 4 > Flare > repeat
Levels 58-81
At level 58, the Umbral Hearts attained from Freeze allow for casting two Flares in a single Astral Fire phase instead of just one.
Blizzard II > Freeze > Fire II x 3 > Flare > Flare > repeat
At 70+, use Foul as needed, it is strong AoE damage and at 80+ can also be used for movement/weaving. Skip a Fire II cast if things die quickly or you want to use Triplecast, prioritizing getting the Flares off in time.
Levels 82-99
High Blizzard II > Freeze > High Fire II x3 > Flare > Flare > repeat
Continue to use Foul as previously mentioned.
High Blizzard II and High Fire II automatically replace Blizzard II and Fire II on your hotbars at level 82, and have the same exact use. Skip a High Fire II cast if things die quickly or you want to use Triplecast, prioritizing getting the Flares off in time.
You will generally ignore the Paradox generated each cycle unless you have a higher HP target to kill in a pack of mobs.
Level 100
High Blizzard II > Freeze > High Fire II > Flare > Flare > Flare Star > repeat
Continue to use Foul as previously mentioned. The introduction of Flare Star makes it far more valuable to rush Flares to get Flare Star off instead of using additional High Fire II casts.
There can be value in weaving Transpose to skip the High Fire II and especially the High Blizzard II as well See the AoE section of the main guide for a better explanation.
Here also as little cheatsheet if you want to save it: