After these days of cramming, Dorothy basically looked and acted like a local now, so she wasn't unfamiliar with the concept of Spirit Ruins People.
She'd already learned the principle behind the phenomenon of Spirit Ruins before—that is, the erosion of reality by the Spirit World. When powerful creatures from the Spirit World invade reality, the Strength of the Spirit World seeps over with them, ultimately fusing with the real world and forming a special space like a ghost or an inner world, something in between reality and illusion.
And Spiritual Realm Creatures that have just come from the Spirit World into reality can also use the Spirit Ruins to complete their transitional adaptation to the present world. After all, the Law of reality differs from that of the Spirit World; they need a period of adaptation and transformation before they can become powerful again.
