Edward Bulwer-Lytton is one of the most important figures in Victorian occultism who you've probably never heard of, in part because Lord Lytton was a man before his time. He was likely a practicing occultist who invented the occult novel with his book, Zanoni. The concepts of the “dweller on the threshold” as well as the magical power of “vril,” an occult energy like astral fluid or akasa can both be attributed to Bulwer-Lytton’s novels. He also predicted the cataclysmic impact of nuclear power and eugenics on civilization.