Here is a short Len x Rin doujin that I got off of Suruga-ya. I think this doujinshi is based off of the "Daughter of Evil/Servant of Evil" songs. This doujin is mostly story with the "action" being very short aka only a couple pages. Len and Rin have bittersweet sex, there are tears being shed by Rin. It looks like this takes place before Len kills Miku, I think she was known as the Daughter of green in the song. I am probably wrong though. It has been so long since I read the subs of that song or watched the video.
I hope everyone enjoys!
PS - Sorry for the blurryness around the bubbles near the binding. The doujin was bound very tightly and it was hard to get the pages straight. I don't like debinding my doujins. I like to keep my books in one piece.
http://www.mediafire.com/file/aadi4gpbvnj87o8/%2528%25E5%258B%2587%25E8%2580%2585%25E6%25A7%2598%25E5%25BE%25A1%25E4%25B8%2580%25E8%25A1%258C%2529_Last_Farewell.zip/file