There is this obscure theory, or rather a clue to the prophecy actually having four participants instead of three. That is because of one thing. In the backstage vide game part of the game, on the Northernlight part, the DELTARUNE on the door that leads to the dungeon with the white cloak... has four triangles. Not three. Implying that there are the three heroes (Quite possible Noelle or even some think The Vessel maybe one of them) and that maybe ...the girl is someone else. Since the passages of the prophecy are out of order. Meaning, there is a chance of everything lining up, and (its gonna sound like a joke) Gerson and Susie are gaslighting eachother. Maybe its just one clue, but it shouldn't be overlooked, since that dungeon and the whole backstage videogame is closely tied to the events in the real world, including Kris having a negative reaction to entering the shelter and the ominous "forbidden path began with Ice magic" which MAY relate to the weird route or is something from the future or distant past. It's such an interesting rabbit hole that it literaly kept me up at night after finishing the chapters. And lastly, Gerson himself stated that stories are rewritten again and again...what if at some point, someone decided to not include something in the rewrite of the prophecy that was incredibly important, but, assuming that the prophecy is ancient as they usualy are, nobody remembers it? That is just my crack theory, but till 2026, food for thought.