Who is Kiera Saltera/Marie Skibbow from The Neutronium Alchemist Consolidation and what is their importance?

Marie Skibbow is the middle daughter of Gerald and Loren, who run away from Aberdale before the outbreak of the possessed virus, but he cannot escape possession in the fall of Lalonde. Kiera Saltera, Marie's possessor, is the socialite wife of a failed politician. Following the fall of Lalonde, she travels to Valisk and becomes the leader of the possessed uprising on the habitat.