User blog comment:Sorairo/Song Analysis/@comment-4010415-20130829063214/@comment-15108745-20130829123612

I don't see how "day and night will sever" means that there is unending darkness.

I read it as some kind of disruption of the natural order. Day and night are naturally part of the day cycle. And if they are severed, that means they're unnaturally seperated.