This info just dawned on me, and after testing, this makes a lot of sense.
If an enemy uses spells 49 through 93, the spell selected is almost always (number-48) that targets all enemies (the characters) by default. If the spell has an overriding profile, such as Flare (the twin spell), the spell's data is used instead, but the graphics inherits that of Cure4. Cure4's spell index is 17, Flare's index is 65, and the different between them is 48.
This phenomenom is most notable in the Dark Elf's battle script, where it exclusively uses this behavior in its battles script.
I accidentally stumbled on it while trying to make the dolls use Edge's Image spell instead of Blink, but caused the monster to cast Sight instead (which is explained by my findings).
We have EVEN MORE themes now, but some old ones are gone...