I can't speak for Healy, but I noticed that, for example, stunned, burned or chilled enemies were suddenly weak to fire and ice when being hit with Desert Dagger and Frostblade, though I ultimately thought it was an intentional design choice.
Hmmm, well, at times it seemed like the "WEAK" and "RESIST" icons would trigger at random. I remember one enemy (maybe it was a boss?) where a character was using a thunder-powered weapon against it, but while it showed the "WEAK" icon, no damage was being displayed. I hope this helps!
