I believe if the sword has an INT requirement, the damage will scale as such, but of course it will default to STR scaling. I had done this accidentally when playing with my holy swordsman class and noticed it definitely scales with STR regardless of element, but I didn't play with it often enough to say with certainty if the damage also scales with the appropriate elemental skill (hydro, aero, etc)--but there's a 99% chance it does, instead of Warfare. (warfare is the phys element basically)
