My statement is me recalling that the last boss of this series are tough and that if this were made today, and not as a remake, it would probably be a very easy boss (or an overly tough one). That is all really.
Honestly it highly depends on how well you know the game, how well you know how to farm it, and how much your willing to exploit him. (As well you can power him up several times) I tried to fight him blind the first playthrough and found him nearly impossible. Then I used a guide the same playthrough and beat him first try. So I'd say he is probably easy if you really know what you are doing, and very tough if you do not.
Good old Romancing Saga final bosses. Back when all games weren't trying to be pathetically easy or stupidly difficult. Not that you couldn't cheap many of them out mind you.