How do you get the ultimate keyblade on Kingdom Hearts 2

In order to get the ultimate weapon you have to have all the shards, crystals, gems, and stones.Yoy also have to have 7 orichalcum+,and i think 7 regular orichalcum,too.after you have all of that you can go to a moogle or a synthesis shop to synthesize the ultimate weapon.The ultimate weapon is a powerful weapon and it really helps when you want to beat sephiroth to.Well that's all i got to say, PEASE!!!!!