Dimensional Key

With the addition of the Ancient City and the theorized portal, something that could be done is add an official key that can either be used to open the massive monumental portal, or it could be used on a nether portal. The key would be in three pieces, one in the over-world (the ancient city), one in the nether (the bastion), and one in the end (the end city). Since the ancient city is end game anyways, it would help the flow of progression so someone can’t immediately spawn and go straight to the theorized dimension.