To clarify on the matter of the Materia Blade, one's Brave is irrelevant to finding the item, since one will always find the Materia Blade at that location. There is no alternate item. The other Move-Find locations at Bervenia Volcano, however, follow the normal rare/common item rules.

The Materia Blade, when viewed in the menu, bears a superficial resemblance to Cloud's Ultima Weapon in Final Fantasy VII. However, there is no Ultima Weapon or "Ultima Blade" in FFT. It's probable that someone simply confused the games.