The author fashioned General Zaroff to fit the plot. The story is about a man who is being hunted like an animal. There has to be a hunter. But what kind of a man would make a practice of hunting and killing human beings? He has to be one who is used to killing people. That suggests a military man--but not an American, because American readers would not like to think of their soldiers killing innocent civilians for sport! He would have to be rich enough to own his own private preserve for hunting. An island is a good setting because it makes it impossible for the prey to escape. But why is he living away from his own country? And what country? A military officer who is not living in his own county might be a Russian who had to flee from the Bolsheviks. The story was written in the 1920s, shortly after the Russian Revolution. A great many upper-class Russians were fleeing to foreign places in those days. If the story had been written in the late 1940s, the author, Richard Connell, would almost certainly have made the hunter a high-ranking Nazi SS officer. Being rich, Zaroff has cultivated a taste for luxuries. There isn't much he can buy on an island, but he can indulge in gourmet food and wines. He is definitely a sadist. He is an aristocrat, an elitist, undoubtedly a strong support of the Czar. No doubt he was responsible for all kinds of cruelty in his home country. Since he must spend a lot of his time alone, he has acquired a broad education from reading. He must have also traveled a great deal and met many interesting people. He is sophisticated. He undoubtedly knows several languages, including French. His English is very good, although he does not say where he learned it. He seems very intelligent--which explains why he is so easily bored. If a man can get bored with hunting tigers, he must bore easily. Zaroff is a fictitious character created to fill a plot need. He is just barely believable. He requires what Coleridge called "a willing suspension of disbelief." That is to say: Can we believe that such a person could actually exist anywhere in the world?
In "The Most Dangerous Game," General Zaroff is portrayed as a complete savage, albeit one with a veneer of civilized manners overlaying his savagery.
Zaroff's savagery is, of course, on full display in his hunting of human beings and his complete lack of any sympathy for them.
At the same time, he has some superficial aspects of civilization about him. He has (affects?) aristocratic manners and fancies himself superior to the common run of people, especially such riffraff as the sailors he traps and hunts.
Overall, then, Zaroff acts (in trivial ways) like a sophisticated and civilized man, but his more important actions show him to be a ruthless killer with no other aspect to his personality.