Well, first of all, that doesn't go against the story. And it IS possible. However, not for typical Elynians. I won't say much more because that would spoil stuff for other people down the line. Normal Elynians, that is, everyone living within the cities, will have their consciousnesses destroyed by the act of devouring that the Tenebra do. It's not so much against the story as it is against the premise of the world.
Her personality is alright, however, the story behind it is nigh impossible.
However, the clash of consciousnesses that a new-born Abyss undergoes can leave the consciousness that wins fractured(in this case, unable to speak and/or feel).