Source of the Blue

The Source of the Blue (蒼の根源), also called the Master Unit (マスターユニット), is a sphere of Blue placed in the depths of the Boundary.

In XBlaze – Code: Embryo, Es, after inheriting the Embryo from Hinata Himezuru, could hear a Discover Call from the Source of the Blue laying in the deepest part of the Boundary. After coming into contact with it, she learned that the Embryo is a threat to the world, and cannot exist within it – should it return to reality, it would cause more distortions in phenomena.

Trivia

 * Nu-13 mentions the Source of the Blue when performing her Astral Heat.