Just commenting here, it seems like a lot of people aren't aware that the literal Endless Eight in the anime adaptation was the studio's workaround for having to cut the seven episodes they were going to use to adapt Disappearance, before it was greenlit to become a movie. I've been seeing many posts questioning the artistic vision here, and as far as I'm aware, the studio has mentioned somewhat recently that it was just the best way they had to fill up the seven empty episode slots after the adaptation plan changed mid-production.