Didn't Isabella get Vlad's Ring of Immortality in the End Times, maybe that is keeping her spirit alive after so long, would also go well with her wedding dress if that idea is true (wearing her departed husband's ring).
I hope the Stormcasts get a named character from this, that is not Hammers of Sigmar maybe Hallowed Knights since some of the models shown off at Warhammer Fest was in their colours.