you know libel basically means slander right? Blood Libel means "fake news" essentially by definition. you want to call it Blood Rituals or something like that, not Blood Libel.
li·bel
[ˈlībəl]
NOUN
1. law
a published false statement that is damaging to a person's reputation; a written defamation.Compare with slander.
synonyms:
defamation · defamation of character · character assassination · calumny · [more]
VERB
-
law
defame (someone) by publishing a libel.
"she alleged the magazine had libeled her"
synonyms:
defame · malign · slander · give someone a bad name · [more]