Congrats on the clear!
I know that The 7th Saga is supposed to be quite difficult..., and it does require some grinding to get past certain parts for sure, but for some reason, every time that I played through this games, it never really seemed overly difficult. (And if I recall correctly, I played through the entire game once with each character being the main character and twice for Esuna.) Now, I did pretty much every time let the Sky Rune Apprentice join me, so I was able to avoid that fight, which is supposed to be one of, if not the most difficult fights in the game.