Does anyone know the track/song in the background playing throughout these anime trailers?

https://www.youtube.com/watch?v=eMJHWAdWxjA https://www.youtube.com/watch?v=RkbrtEk9440&list=WLAFCCDC52D024DCB7 They are the trailers for Blood-C and The Last Dark film and it's been killing me. I've been looking for hours. ;w; If you don't know, maybe we can expand the search! afospagjodspyearw ~T