It was not the kind Elias had built, not the defensive construct of someone trying to keep something out. Something different. A seal. Two-essence binding, which was significantly more complicated than a standard defensive barrier because it required the participation of both essences being bound to it and she did not have the demon's willing participation.
She did not need its willingness.
What she needed was its essence, which it was producing in quantity, and which the binding could draw from ambient output rather than active contribution. The seal drew from her own core and from the demon's ambient essence field simultaneously, the two sources becoming the construct's sustaining mechanism, and the construct that arose from that mechanism was not a wall.
It was a room.
A contained space that required both sources to remain active for its integrity. When one of those sources ceased to produce, the construct would fail. When that source was the demon, the seal would end.
