>>546022091
That wouldn't be the only part of the prophecy derailed by a shadow crystal boss. There's an unused prophecy line in the files that says:
>AXE CARVED BY THE TORTOISE'S GRAND HAMMER.
Which also fits Gerson's description for chapter 4:
>Chapter 4, The Trials of the Holy Hammer.
>A great smith gives the heroes a terrible weapon.
But obviously we don't get the axe unless we go out of the way for it. Yet the image for that prophecy line is still seen in the 3rd Sanctuary, so it's not entirely unused. It's more like Gerson deliberately broke away from the prophecy.