What do you think happens to Zaroff? What are some possible endings for the story?

Zaroff has been killed by the end of the story. The only other ending would have been Rainsford's death. The intent of the hunt was to kill or be killed.

Zaroff actually fights Rainsford and ends upp being fed to his own dogs. In a story like this, we expect the protagonist to come out on top. I might have Zaroff win. After all the guy went to a lot of trouble to set this whole thing up!