Sacred Zone is Kyouka's unique field action that allows her to pass through 'immovable' Blare.
Kyouka creates a barrier around herself such that she is temporarily immune to the effects of the Blare, which allows her to move through 'immovable' Blare.
As with other field abilities, too low of an action level will prevent her from moving forward. In those cases, one must revisit the area once their action level is higher. Also, Action Level rises when particular quests are cleared.