Black Mages
In a party a BLM is your demolitionist. They explode things hard and do it fast as they can.
They come in two modes: Astral Fire and Umbral Ice.
Astral Fire is your damage mode, dropping massive hits and draining your mana pool. This is not an issue, thanks to...
Umbral Ice is when you drop your tech and dot abilities, like...
Thunder, Thunder II, and Thunder III for dot, always have this on if you can, after getting thunderstorm pop a thunder of any level for free with bonus damage. Use your own discretion on targets for these.
Sleep for tech. This is good for if the other dps in your party is a focus type, especially after getting Deep Sleep making it an AoE ability, sleeping whole hordes, and reducing the weight on your healer and tank.
At the end of each phase of Astral Fire and Umbral Ice a BLM should use...
Transpose switches between your modes, allowing you to not have to use spells to build from zero stacks. It is however worth noting that it trades a full stack of UI/AF for one alone.
Bits and Ends
Flare
A good end to an Astral fire mode, it does drain all remaining mana and transpose should always be used right after.
Convert
Good for a double flare, not my preference though.
Swiftcast
Anyone planning to run a caster or use magic should level THM to 26 for this. Instant raise will bring SMN, SCH, and WHM all kinds of love.
That's how I use BLM. Other ways are also correct, but this is my advice on how to do it.
In a party a BLM is your demolitionist. They explode things hard and do it fast as they can.
They come in two modes: Astral Fire and Umbral Ice.
Astral Fire is your damage mode, dropping massive hits and draining your mana pool. This is not an issue, thanks to...
Umbral Ice is when you drop your tech and dot abilities, like...
Thunder, Thunder II, and Thunder III for dot, always have this on if you can, after getting thunderstorm pop a thunder of any level for free with bonus damage. Use your own discretion on targets for these.
Sleep for tech. This is good for if the other dps in your party is a focus type, especially after getting Deep Sleep making it an AoE ability, sleeping whole hordes, and reducing the weight on your healer and tank.
At the end of each phase of Astral Fire and Umbral Ice a BLM should use...
Transpose switches between your modes, allowing you to not have to use spells to build from zero stacks. It is however worth noting that it trades a full stack of UI/AF for one alone.
Bits and Ends
Flare
A good end to an Astral fire mode, it does drain all remaining mana and transpose should always be used right after.
Convert
Good for a double flare, not my preference though.
Swiftcast
Anyone planning to run a caster or use magic should level THM to 26 for this. Instant raise will bring SMN, SCH, and WHM all kinds of love.
That's how I use BLM. Other ways are also correct, but this is my advice on how to do it.