Raymond Lully was a Majorcan writer, Philosopher and Logician. In The Last Door mythos he invented the serum that is used to lift the veil. His work ´Ars Generalis Magna` ("The Ultimate General Art", published in 1305) is mentioned in H.P. Lovecraft´s story `The Case of Dexter Ward´, written in early 1927. Lull's art was originally designed as a tool to convert Arabs to Christianity through logic and Reason. His methodology was based on a device used by Arabic astronomers, called a Zairja.
Raymundus Lully may be the only character in The Last Door who has both an "in-game persona" and a "historical persona". The two personae are nearly identical, though obviously the historical Lully did not explore the Veil.