Need help beating Dark Fact?

[Armboy]

My life had meaning while playing Ys I, it was all wonderful until Dark Fact happened... lol Hardest SOB I've ever encountered. Just tried 4 times to beat him and i am already frustrated to know the hundreds more to come.
Piece of advice: DON'T GIVE UP! (Like i just did for today haha)
How do ppl dare saying Vagullion is the hardest boss in the game?!
Anyway, this video: http://www.youtube.com/watch?v=eOginOZl1Pk has come in handy for many it might help you too.
Let me know if it works ;)