Blood rituals are known in New Eden, and are a staple of Sani Sabik rituals.
At one point, the blood was only used in initiation rituals, but over the centuries the Sani Sabik began involving it in all rituals in an effort to find eternal life. Some of their sects use rather inoffensive rituals, while in others they are quite gruesome.
Certain sects supposedly keep blood farms of people to be repeatedly drained. There are even rumors that some sects have cannibalistic and necrophiliac rites.
The most notorious sect of all, the Blood Raiders, once drained children, but recently began to drain cloned people after being taken over by Omir Sarikusa.