[Cao Ni Ma]

Originally Posted by LyricalAura

Which character is that at 1:07? At first I thought it was Eva-Beatrice, but the ruffles and hair don't match...

Spoiler for EP8:

Yukari, maybe? It looks like she has the key to the Book of the One Truth.

Also, is that a one-frame-long spoiler image of Ikuko and Tohya I see at the end?

Yeah, I remember someone taking a snap during a teaser and its just what you say. The woman though with the key though is a big unknown but chances are you are correct.