User blog comment:Njalm2/Direction of the Coven/@comment-18812574-20161201182409/@comment-24384232-20161202025604

Huh, forgot that it ate my reply.

Well here's my theory regarding the Soul Fragments. As Yhwach's primary ability was the sharing and acquisition of spiritual power, those soul fragments would retain that aspect. Furthermore as the son of the Soul King, his status as a bridge between worlds is uncontested. Therefore, the Soul Fragments if properly attuned/aligned could make for powerful cores for the Lodestones, allowing them to merge the physical and spiritual worlds together. If this was included Id imagine that their plan would be in multiple phases.

The first is the establishment of their stronghold in the human world. While their our gathering the fragments the process can begin, and they can start converting mages and those like minded to their cause. But with Soul Society getting in their way I imagine they would try to remove that threat as well. Probably by borrowing from a previously failed attempt by using the Valley of Screams as a hammer to force the spiritual realms of Hueco Mundo and Soul Society to collide, thereby removing the Hollow and Shinigami menance in one fell swoop. Doing so would require mages capable of controlling spirits which they have a few notable members of.