Talk:Undine/@comment-25439502-20140919201416/@comment-25035274-20140919202211

It's caused by the strengthening of their Demonic Energy. As they have sex more, their Demonic Energy grows stronger. Eventually, they level up(sort of), and become much more powerful but also more lusty. At that point, they become a Dark Elemental.

As far as we know, only the four main elementals (Undine, Ignis, Gnome, Sylph) can become Dark. The Dark Matter cannot become Dark because it ~is~ Dark.