What does the last line of the story tell us about Rainsford's evolution as a character?My question is about this passage: "He had never slept in a...

The last line of the story reflects Rainsford's evolution as a character in that he has survived "the game." It was a game he did not want to play to begin with, but was rather forced into. His resourcefulness, bravery, and cunning served Rainsford well in the challenge put on him by Zaroff. In the end, after he has outsmarted Zaroff and beaten him back to the house, he is able to sneak into the bedroom and overtake the general in hand-to-hand combat.

His reflection about having never slept in a better bed shows that he has come full circle. His journey began on a quest to hunt for entertainment, and in essence, ended victoriously after having been the one hunted. The irony is immense!