Thread:Night Vision/@comment-4762852-20160720204024/@comment-8695373-20160724140921

Seithr does not put people in a trance. If you talk about the part when she lost control over her body and spoke like a robot, that is because (spoiler) Noel is an artificial human, like Nu, and she has programms in her head, that sometimes take over her and turn her into a mindless weapon which she was meant to be. Read the Boundary Interface Prime Field Device article. I also suggest you to play the games, since the anime left a lot of stuff unexplained.