She Is My Sin Lyrics

Lyric discussion by EntropyofKura 

Cover art for She Is My Sin lyrics by Nightwish

This song makes me think of the Grigori, the angels who were intended to watch over the early earth but fell because of lusting for (and mating with) mortal women.

This might just be because I saw the lyrics with "Fallen" capitalized in "I am the Fallen", but either way I think it seems like a pretty valid interpretation.