Ley lines and AoE

[Iagainsti]

You always have enough MP for 4 F2's. If you have enough MP to cast a 5th because of a "lucky" MP tick you need to cast Flare instead anyway as you won't have enough for Flare after a 5th F2..
If you're less than 3200 MP and you're trying to cast another F2, you won't have enough MP for Flare.
I have approx 11400 MP which is pretty standard.

Thank you, so 4 Fire II is the magic number.