The Sisters of Battle Previews continue this morning on Facebook
In today's preview "Vessel of the Emperors Will" and "Purity of Faith"
via Warhammer 40k Facebook
https://www.facebook.com/warhammer40000uk/photos/a.1576243776029589/2514990085488282/?type=3&theater
Acts of Faith by those on high attract and increase the Emperor's grace, granting further boons to the Sisters of Battle.
The Sisters of Battle are famously iron-willed, and the Purity of Faith Stratagem allows you a second chance to resist a psychic power targeting your units.