Board Thread:Dark Souls/@comment-122.148.246.88-20130127080444/@comment-5264386-20130127094724

Only a few weapons actually go up to S, such as the Black Bow of Pharis. The only way to increase a weapon's parameter bonus is to upgrade it, but I believe that the Dragonslayer Spear's parameters do not increase, only it's damage. You can check out our page on it for the whole upgrade table.