Faust stole the Pandora Box as well as a few Full Bottles from Build! NightRogue does not back down as he aims to claim all of the Full Bottles left in Build’s possession. The only ones left behind are the Lock and Dragon Full Bottles. The Key Dragon form can only be accessed by Build, however, the power within the Dragon Full Bottle is so strong that it becomes impossible to control even in a Best Match configuration! In desperate circumstances, there doesn’t seem to be much of an alternative, until Sento thinks of one… if the Dragon Full Bottle can be used in the CrossDragon, it will become compatible with the Build Driver!