I think that if there was, they would have found a way to incorporate it into the game, but throughout all the eras, all magical doors and locks that the Kingdom of Zeal put into place are found and opened. All the chests that need the pendant to be unlocked, all the doors, etc. stem from Zeal. It is completely believable, since Zeal is only one continent in the sky, that the amount of said items found in the game to be unlocked are exactly the number that withstood the test of time. They are items that were believed to be the pinnacle of Zeal evolution, but they weren't necessary the pinnacle of human evolution. No matter how good the weapon, or the warrior, there always comes along one that is better. It's only a matter of time.