When Vanessa goes into trance, she talks about a "green place" where "the Porters are dying". This is a reference to the characters of Jane and his father in "Tarzan of the Apes", by Edgar Rice Burroughs. The novel takes place approximately at the same time as the series, and matches its the Victorian setting.
"Enter Proteus" appears eight times in William Shakespeare's The Two Gentlemen of Verona (1952), but the one shown is from the start of Act 2, Scene 6.
Dr. Frankenstein and Vanessa recite lines from William Wordsworth's Lines Written in Early Spring.
Brona derives from the Gaelic 'Bronagh', for "sorrow".
Madame Kali identifies a presence as "Amunet". Amunet (the hidden one) is a primordial goddess in ancient Egyptian religion. Thebes was the center of her worship through the last dynasty, the Ptolemaic Kingdom, in 30 BC. She is thought to have existed prior to the beginning of creation along with three other couples representing primeval concepts.