Elwin Ransom
Elwin Ransom may be based on C. S. Lewis' friend J. R. R. Tolkien ("Elwin" means "Elf friend" in Anglo-Saxon), though he seems to have autobiographical elements. In "That Hideous Strength" Ransom, with his royal charisma and matter-of-fact breezy acceptance of the supernatural, appears less like Tolkien than like Charles Williams (or some of the heroes in Williams' books).
A Voyage to Arcturus
The novel was a central influence on C. S. Lewis's 1938–1945 "Space Trilogy". Lewis also mentioned the "sorbing" (aggressive absorption of another's personality into one's own, fatal to the other person) as an influence on his 1942 book "The Screwtape Letters". Lewis in turn recommended the book to J. R. R. Tolkien, who said he read it "with avidity".