In my recent round of hack testing, I have found that monsters that would have been normally been immune to Quake (weak vs Wind/Air elemental) like Arachne, Clapper, or RockMoth are not immune to Quake when they are summoned. There is obviously something going on that prevents the code that gives them immunity to not work. Affects all SNES versions of FF4 and doesn't affect FF4A at all.