I once told a friend how to unlock the Sacred Realms, but I forgot to tell him to talk to Curly twice to get this item, and he couldn't get into the Prefab Building once he beat The Undead Core.
He had to go through the Final Cave backwards so he could get the Iron Bond to unlock the Sacred Realms, go through the Final Cave again, beat all the bosses and get into the Sacred Realms.
Seriously, considering the fact that there are a lot of things that you have to do to unlock that final stage (most of them, at very specific moments and with only one opportunity), was it necessary to require also an object made with the only purpose of unlock that secret stage obtainable by talking once again with a character you just saved thousands and thousands of times?
