What are the different forms/ways blood libel presents?
Fundamentally, blood libel is the accusation that somebody (usually but not always Jews) is murdering innocent people (usually but not always children) to use their blood, flesh, or some other thing their bodies produce, usually for medicinal, nutritional, or ritualistic purposes. It's a very old allegation that's been used against many people throughout history.
The most common forms today are allegations of cannibalism (especially infant cannibalism) and allegations of ritual child sacrifice. (The Satanic Panic was really big on this.)
A slightly less common form are allegations of adrenochrome harvesting - supposedly, children are killed so the adrenochrome can be extracted from their bodies because it has allegedly has strong hallucinogenic and anti-aging properties. (In reality, adrenochrome can easily be synthesized in a lab, and it is not a hallucinogen, nor does it have any anti-aging properties.)
An unusual form you probably won't come across unless you get into New Age conspirituality are claims of loosh harvesting. This conspiracy theory claims that alien beings are intentionally keeping humans miserable so they can collect a special energy their bodies create under stress.
The core of blood libel is accusing people of slaughtering innocents for some kind of ritualistic or consumptive purpose, and it will almost certainly mutate into different forms in the future - if it hasn't done so already. Blood libel allegations are also pretty much always packaged in with a lot of other standard conspiracy theory tropes, which you should familiarize yourself with here:
Check your conspiracy theory. Does it sound anything like this?
Check your conspiracy theory part two: double, double, boil and trouble
Check Your Conspiracy Theory Part Three: Babylonian Mysteries?? In My Religion???
