I can't seem to find the old thread, but if someone finds it, please merge the threads.
The FF4A specfic weaponry: Lightbringer, Fiery Hammer, and Abel's Lance all have a chance to cast a spell, particularly when the attack command is used. The frequency of the spell casting is unknown (I believe Abel's Lance depends moreso on Kain vs target's level, but I could be wrong).
The spell cast is powered by the respective stats that normally power the magic. The status of the character does not matter as the spell is cast independantly of the attacker's current status. However, Blind is the only impactful status that actually affects the magic damage dealt.
We have EVEN MORE themes now, but some old ones are gone...