I don't think it has anything to do with the night whatsoever... if you ask me, it sounds like he was hit over the head... or shot... or something to that effect... and in his last moments he is at peace. Able to forget all of the horrid things he has seen and done, and is simply waiting for the darkness of death to consume him... waiting for the night to fall. At least that's how I'm reading into it.
I don't think it has anything to do with the night whatsoever... if you ask me, it sounds like he was hit over the head... or shot... or something to that effect... and in his last moments he is at peace. Able to forget all of the horrid things he has seen and done, and is simply waiting for the darkness of death to consume him... waiting for the night to fall. At least that's how I'm reading into it.