An extensive pipeline of energy that flows around the globe, known by various names such as the Earth Veins, Spirit Veins or Dragon Veins.
Previously, they were utilized by the alchemist Carol together with Château de Tiffauges as she attempted to dissect and analyze the world.
However, that was stopped thanks to the actions of S.O.N.G. and the Symphogear Adaptors.
The Alchemists have stated they need an accumulation of life energy to transmutate the Divine Power,
and knowing this, S.O.N.G. has theorized they may attempt to use the Leyline to collect the life energy of the very Earth itself.
Plans are now being put into motion to hopefully forestall this possibility.