Let’s talk about Blue Magic for a moment. Blue magic isn’t really all that important to the Final Fantasy series; it’s more or less a sideline for completists. All the really important magical effects — direct damage, healing, buffs and debuffs — are pretty much covered by normal spells. So what does that leave for the Blue Mage to discover?
One of the things it leaves is quirky effects that don’t play by the normal rules. Things like the “1000 Needles” spell (aka “Blowfish”), which always does exactly 1000 points of damage to its target, without the random element found in all other direct-damage spells. 1000 points may sound like a lot, but only if you’ve never played a Final Fantasy. The numbers can get pretty large; at the point I’m at in FF6, my regular melee attacks routinely do more than 1000 points without costing any mana, and it often takes two or three hits to kill something. So in normal circumstances, the 1000 Needles spell is pointless. Its advantage is that it always does 1000 points of damage, regardless of the target’s defense. Monsters with abnormally large defense ratings, and special attacks to overcome it, seem to be a big part of this game.
Regular magic has spells that heal an amount of damage based on the caster’s Magic Power stat, and deals damage on the basis of Magic Power and the target’s Magic Resistance and elemental vulnerabilities. Blue magic has spells that heal damage based on the caster’s current hit points, or deal damage based on how far you’ve walked throughout the game so far. I think my favorite examples of how absurd this can get is the suite of level-based spells. In FF6, this consists of L.3 Muddle, L.4 Flare, and L.5 Doom, and possibly others I haven’t found yet. Muddle, Flare, and Doom are all normal combat spells, respectively causing Confused status, massive non-elemental damage, and a chance of instant death to the target. The number indicates what sorts of creatures are affected: L.3 Muddle casts the Muddle spell on all enemies whose experience level is a multiple of 3, and so forth. This is a blatant intrusion of the stats into the reality of the world. Either the people in the gameworld are aware of the “experience level” mechanic, or they probably find it very confusing how these spells consistently work on some types of monsters and not on others, with no obvious reason. Back in FF5, there was a puzzle element to all this. The variables governing the effects were non-obvious and undocumented, but could be figured out through observation. FF6 uses a lot of the same effects, so the puzzle aspect is gone.
The least abnormal blue spells are the ones that simply do elemental damage on the basis of an element not used in the normal spell tree. From FF1 onward, there’s been a standard sequence of fire, cold, and electrical damage spells, each coming in three levels of severity. Spells doing air-based or water-based damage were outside of this tradition, and assigned to blue. By FF8, they had been folded into the regular spell list. Today’s quirky exception is tomorrow’s normal.