My personal theory is that the current Raeliana is actually Beatrice, and that Beatrice's soul was currently in Eunha's body when the whole black magic happened, which makes more sense (and a better plot) than "hey let's randomly grab some random Korean girl from another universe just so we can have a Korean heroine".
The book is titled "Beatrice" and in said book, Beatrice and Noah are destined for each other... but if current Raeliana is actually the real Beatrice, then that still holds true.