How many spells is that? I only think of a couple, Quake, Meteo, and all of the summons. Any others?
Ninja attack spells, Comet (Flare is not since targeting is forced by the Twin command), and a number of enemy attack spells.
Even the Cure/Healing Staff magic is part of this as well.
The enemy spells include:
ColdMist (Mist Dragon's monster attack)
Explode (Mombomb attack)
Poison (Dr. Lugae's attack, as useless as that is)
Big Bang (it explains a lot)
Pollen (plant enemies use this)
Fission (Last Arm's suicide attack)
Heal (Golbez uses this "hidden attack" to simulate Rydia healing the party)
All the HP based attacks (those that use the enemy's current HP or the target's max HP)
Quake (enemy's version)
Emission (Red Giant's attack, FF2US name)
Heat Ray (Red Dragon's attack)
Odin (Odin summon monster battle attack)
MegaNuke (Bahamut's attack)
We have EVEN MORE themes now, but some old ones are gone...