How is BLM?

[Frizze]

It's like, why do we stick that in when we have access to F3 & F4?

It sounds like you got this, but ill put a little bit of the math in a reply incase anyone searches up this topic and has more questions.

So for Fire 4, the reason it cant be our only attack spell is that it doesnt refresh the astral fire buff window. If it was all we had access to, then our "burn" phase would be F4 F4 F4 F4 and then we would be at the limit of the timer and need to switch back to ice quickly to keep the Eno buff rolling(the alternative of only using 4 or 5 buffed spells every 30 seconds is much worse). We get 6 of these spells in(plus other spells) per cycle rather then 4 by using the rest of our toolkit.

The reason that Fire 3 doesnt take up the mantle of primary nuke is cost and strength. At full power Fire 3 is an approx 646 potency attack spell(base potency 240, 1.8 multiplier for astral 3, 30% boost for M&M trait, 15% boost for eno). It takes 3.5 seconds to cast, along with 4000 mana. At the same power level Fire 1 is an approx 484 potency spell(base 180 same boosts). It takes 2.5 seconds to cast, along with 1600 mana. So with F3 only your burn phase would last 7 seconds, would only be 2 spells before you couldnt continue, and would be roughly 1292 potency(or 184.6 pot per sec). With F1 only you end up with a phase that goes 15 seconds over 6 casts, and an approx potency of 2904(193.6 pps). Fire 1 also has the bonus of a 40% chance to give you a free cast of F3(no mana, no cast time - still triggers GCD though) raising the average value of an F1 cast(assuming all procs are used without being overwritten) to roughly 742 potency(so effectively a 212 pps rotation). But Fire 1 only still doesnt outpace the version Tint spelled out that included Fire 4(for comparison, Fire 4 is roughly 807 pot and the despair at the end of the cycle is roughly 1023 pot - for a burn phase with roughly 279 pps if we ignore the DoT you should have running).