Two men who killed each other in the most honourable way possible - in prose.

I love the story of the relationship between Robert Block and H.P. Lovecraft: two men who killed each other in the most honourable way possible - in prose.

From the Reader's Almanac post, What Robert Bloch owes to H. P. Lovecraft:

One of the stories Bloch wrote while Lovecraft was alive featured Lovecraft as a character, killed by a monster. Weird Tales required Bloch to get the victim's permission before publishing the story, and Lovecraft authorized Bloch "to portray, murder, annihilate, disintegrate, transfigure, metamorphose, or otherwise manhandle the undersigned in the tale entitled THE SHAMBLER FROM THE STARS." In November 1935 Lovecraft responded in kind with "The Haunter of the Dark," in which young Robert Blake (living at Bloch's actual address) is killed by an alien. He dedicated the story to Bloch.

I got to searching this out by listening to Drabblecast 213 – The Haunter of the Dark. Drabblecast is about the most amazing podcast in the entire known Universe btw.

For the full text of the other piece featured on that Drabblecast episode, the poem Fungi from Yuggoth, see Fungi from Yuggoth on the H.P. Lovecraft site.