[@Majoras End]
Eyo, just as a heads up, if Eliza is equipped with the Heavy Blade and the Mystic Dress that she purchased, she would have an extra +1 to STR, VIT, and MAG, because in the old shop, the bonuses were supposed to stack upon the baseline of being a Melee Weapon and an Elaborate Outfit. Basically, in total...

Heavy Blade: +3 STR, +3 VIT
Mystic Dress: +2 MAG and flight capability

EDIT: Also, to clarify, Eliza wouldn't be getting benefits from both her Fist/Mystic weapon and her Melee/Mystic weapon at the same time. Her stats will change depending on which one she's wielding at the moment.