I'm pretty sure this thread has occurred before, but since I think I've beaten it one more time since then..
4 times on Normal mode, the first three being where I choose the Staff and gave up the Sword. (lol noob) The fourth one being Sword, but no Shield.
Once on Expert mode, though I'm working on "semi-"beating* it on that again.
* as in start at the near beginning of Hollow Bastion's first visit and going from there.. I probably had two of my most challenging battles during that time btw. I got beaten by Dragon Maleficent for the first time ever and nearly died to Riku Final (I had one HP at the end of the battle, which ended with me breaking his combo and getting enough MP to do Ars Arcnum, to finish the battle.). I think it was partially due in part to me not grinding at all, before fighting either one of them. I took on Dragon Maleficent at 46 and Riku Final at 47, with Metal Chocobo.