I never tried hades on ruby before. I've defeated him with loads of different strategies. One strategy I used was to set up your party so someone With W summon cast knights of the round and had mp and hp absorb plus everyone had countermime and mime aswell. Everytime he attacked your party members when he had his claws in the ground he was walloped with kotr plus your mp and hp was restored plus everyone was miming it so within a few attacks he was toast.