Bloodbook on the Halfshell Lyrics

Lyric discussion by Southbound 

Cover art for Bloodbook on the Halfshell lyrics by Danielson

I think the "bloody books" are Bibles. They are bloody because of all the blood that went into them and goes on in them, specifically the Cross.

I think if you're thinking along the lines of the "bloody books" being Bibles, it sort of explains itself.