Arthur Machen
Around 1890 Machen began to publish in literary magazines, writing stories influenced by the works of Robert Louis Stevenson, some of which used gothic or fantastic themes. This led to his first major success, "The Great God Pan". It was published in 1894 by John Lane in the noted Keynotes Series, which was part of the growing aesthetic movement of the time. Machen's story was widely denounced for its sexual and horrific content and consequently sold well, going into a second edition.
God Mazinger
The manga, although it shares some similarities and the same premise, differs from the anime with a more mature tone and also has a different conclusion. It was originally published in tankōbon format by Shogakukan in 1984. It was later re-printed in 1986 by Kadokawa Shoten under the title of "Majin Densetsu" and also under the original title by Chuokoron-sha in 1995 and Daitosha in 1998.