Bingo. During my first run of Binding Blade, I heard about the True End requirements, but 20x baffled me (I went in mostly blind). So I grabbed codes for the two of them just to make sure. Then it turned out I got the other Divine Weapon anyway afterwards, so I never needed it.
But yeah, that is why I'm curious about SD codes; I really don't know who looked at the Gaiden chapters and thought it was a good idea that you had to kill everyone, but it got through.