I'm not sure about the requirement for all blood magic.
In the Philippines in the Mountain area of Luzon there is a Mambunong who performs the ritual for the living to connect with the dead. He slaughters and tortures many pigs for the ceremony. Some of my family has celebrated this ritual and other rituals for many generations. They do seem to connect with the dead.
http://www.stuartxchange.com/Cordillera.html

The culture is also rife with rites and rituals. Deities are often invoked for health and illnesses in rituals that usually involve the sacrifice of animals and the drinking of tafey (a native rice beer fermented from the red rice variety) in the background of prayer chanting by the mambunong. Of the 40 recorded ceremonies, some are rituals specifically related to illness:
• Ampasit, for sore eyes and sore feet, with a sacrificial chicken offered to the ampasit, pinad-eng, and tinmongao.
• Dosad, for chest pains, the mambunong hold his spear against the chest of a pig and prays. After the pig is butchered and cooked, the mambunong repeats the prayer while holding the spear against the chest of the sick person.
• Sikop or sigop, a ritual for curing coughs, sans sacrificial animal or tafey, utilizing instead salt and ginger that is rubbed on the patient's neck while praying.
• Kolos, for stomach pains and diarrhea, offered to the water-god Kolos, with a pig or chicken and tafey.
• Sibisib, to cure wounds, performed without sacrificial animals, with the mambunong praying while placing the instrument or a substitute over the wound.
• Basal-lang, performed after childbirth to prevent excessive bleeding and skin disease.
• Tomo, a ritual to cure an insane person, a sacrificial dog is offered to departed ancestors believed to have caused the insanity.
• Topya, to counteract a curse or cure an illness or physical deformity caused by witchcraft (padpadja) with sacrificial offerings of dogs, chickens, ducks or goats.

Many blood ritual require blameless blemish-less innocent flesh of any kind. I mostly studied the murderous religion of Christianity it's history and roots. After I read "Beware the world to come", "Our God is your God too, but he has chosen us", and "From Yahweh to Zion Clash of Civilizations" I gave up on all of the fairy tales I had learned before.

The crux of those three book lay out that Moses was a murdering con man and he went up a Volcano and came down gods representative high priest. But the facts are far from what the fairy tales teach.
Now the entire world is dealing with a very effective and powerful conspiracy to destroy everything. They will not just kill the 70 Nations they will kill all because all blood is tainted with the sin even themselves. They actually believe that their god will raise them from a desolate earth that no life exists in. https://en.wikipedia.org/wiki/Vision_of_the_Valley_of_Dry_Bones This is their plan for all of mankind.