I have to commend Peele, and his team, for how hard they are going mixing history and fiction.
The hermaphrodite was Arawak, an actual tribe of South Americans that went extinct.
The biggest thing I'm wondering is what the Book Of Names could be a reference too.
My first thought was the Lesser Key Of Solomon, a book of demon names.
But there's also a book of angel names.
Show might be referencing both since they are also tied to spellcasting in the occult.
Or I could be completely wrong and it's some other shit.
Another cool episode btw.