I would not say it is. Though that fight triggered a Gamefan employee who couldn't beat it in the English release and got mocked a lot.
It's a tough fight like many in that game but I deffinitely wouldn't call in unfair. That said I didn't find anything in V unfair either... But in Lunar you at least know that your party is already set up to deal with the boss you're facing which makes in seem on average easier to me.