7. Manuela and Daniel Ruda
What's true love? In the warped minds of German couple Manuela and Daniel Ruda, it's killing a man together to appease the horned man downstairs.
Back in early 2002, the married lovers (Manuela, 23, and Daniel, 26)—who met through a heavy metal magazine's advertisement section—stabbed their buddy Frank Haagen 66 times, beat him with hammers, drank some of his blood, and stuck the lifeless, decomposing body, which had a scalpel poking out of it and a pentagram carved on the chest, in a coffin that rested next to Manuela's bed.
The Rudas were eventually caught at a gas station during a time period after Haagen's murder in which they armed themselves with a chainsaw and awaited, or kept themselves "prepared," for Satan's next commands. Manuela's later court testimonies included the reasoning that she and Daniel killed Haagen as "Satan's instruments" to "make sure the victim suffered well." She also claimed that time spent amongst a vampire cult in Britain led to her acquiring the taste for human blood.