Couple questions about demons and magic paths

[Baneslave]

Illuminated One: I made some changes and now Phoenix Guard (hurrah for imaginative names!) have second ethereal form. And immortality.

Multiple forms is bit problematic as:
1. Soul Slay doesn't kill completely. (Makes sense if second form is mount or smaller formation)
2. But if multiple forms are used to represent formations, how come AOE spells can only kill one of them at time?

So yeah.