The Hollow was sealed at some point by the ancestors after the formation of the ancestral plane, and many here even argue that (The Hollow) it was more powerful precisely because it existed before the formation of this dimension of spirits, and that to stop it they would need a great sacrifice, and As soon as she possesses Sofia, it is apparently somewhat implied that she feared being detained again by the ancestors, analyzing this whole situation, ancestral magic is dead magic because it comes from spirits, how could the Hollow be a threat to them?, if its power is from sacrifice, is only dangerous for the living, and ancestral magic is the magic of the dead, it's as if their magic was anti-sacrificial magic, is that the justification then? due to their power (Ancestor magic) being beyond her power (sacrificial magic)?