Although the affinity is for all Casters, ideally we assign it to a Black Mage due to their nature of quick MP recovery in Umbral Ice.
SMN and RDM can use Flare Star, but there's a limit to how many Resistance Ether Kits you can bring in. Thus, the only way for non-BLM to use Flare Star is by assigning a Ranged to allocate Lost Cure II as a primary action.
Pure Essence of the Fiendhunter (Ranged) + Lost Cure II grants a potency Refresh, replenishing MP at a high rate.
The benefit of this spell is that it will make all spells instant cast while increasing the mp consumption per spell.
Lost Chainspell will make Lost Flare Star 11k mp, which is impossible in a DRS setting. All players, including Flare Star mage, must be using Pure Essence.
Lost Chainspell is obtained from (Artistry) while Lost Font of Magic is obtained from (Sagacity), a fragment obtained only in Castrum Lacus Litore (CLL), making Chainspell a suitable alternative to Font of Magic.
FoM grants a huge buff in damage while draining MP throughout the duration. Should your MP reaches 0, FoM will fall off pre-maturely. To prevent this from happening, Resistance Ether Kit or Refresh (from a Ranged Lost Cure II) will need to be in effect.
To prevent losing all your MP, use Resistance Ether Kit or request your range to use Cure II instead. Lost Cure II on a ranged with Pure Essence grants (MP) Refresh, a buff that recovers MP better than Lucid Dream.
Pure Essence of the Elder grants an secondary buff to Lost Cure IV, casting Bravery on all party members that last for 60s. Since Lost Cure IV cooldown is short, each team is assigned to only one Cure IV caster.
If there are more than 1 Caster in the party, the unassigned Caster can should use a double DPS Lost Action setup.
All parties will have a Caster assigned to do Cure IV. It is a 60s duration buff, 25 charges and 5s cooldown. Ideally Casters should use Cure IV at pre-pull for buffed damage at the start of each fight, and renew Cure IV every time the countdown reaches 1s ~ 5s. With that many charges, brining up to 3 Lost Cure IV in the holster is possible.