You know how there is anomalies in undertale. Well let's say when the first people that got shot took them allot longer for them to become them and by then almost everyone one hade it in them so everyone new that they would become that so some monsters took there life and others made notes for them to hopefully remember.
When frisk came down everyone was one except Flowy,Torial,The monsters in the ruins and a few random monsters like monster kid was one.
And to cross the barrier you hade to find Asgore's anomaly and make him and yourself cross the barrier.
Also Torial has some idea of it with them not being there self but that's it as Flowy knows all about it and calls them things and not monsters.
I will think of more later
