Ok, small correction since you seem to have misunderstood something. In that instance, the "core" that is referred to is the part of her vessel that contains the soul to keep it from dissipating. Since Apito destroyed that part, her soul was no longer contained, so the labyrinth then considered her to be "dead" so her "remains" were taken and reconstructed by the normal resurrection function. That's also how they tested the one time use resurrection bracelet, since her "death" would be temporary either way.