Who is Uncle Khosrove?

Uncle Khosrove is a character in William Saroyan's short story The Summer of the Beautiful White Horse, which tells of nine-year-old Aram and his adventures with a beautiful white horse that his thirteen-year-old cousin Mourad steals from an Assyrian farmer.
Mourad's behavior is described as sometimes erratic and foolhardy, a trait that allegedly was passed down to him from his Uncle Khosrove, even though Mourad's father was supposedly very pragmatic. In other words, Uncle Khosrove carries the family's "crazy gene" and passed it on to Mourad.
Khosrove is a large, imposing figure with a strong head of black hair and the largest mustache in the area. He is portrayed as angry, irritable and intimidating. He has a very short fuse and will not let anyone speak before him. He is so impatient that he immediately dismisses any issue with the phrase "It's no harm; pay no attention to it." It simultaneously evokes feelings of both humor and sadness.
Khosrove's behavior stems from homesickness, feeling out place, and bitterness at losing the place where he grew up. He has a fierce longing to return to his homeland, so much so that his acrimony and animosity over this loss overshadow anything else that's put before him. It's as if an impossible return to the past is the only thing that will quell his fiery demeanor.

Khosrove is Aram and Mourad's uncle. He is described in the text as being an "enormous" man with a thick mustache, well-known for his fiery temper and irritability. As such, he is regarded to be the owner of the Garoghlanian tribe's crazy streak. He's also known for saying, "It is no harm. Pay no attention to it." This has become a sort of mantra or catchphrase of Uncle Khosrove's.
In the story, Aram relates a humorous tale about Uncle Khosrove. One day, Khosrove was at the barber's having his mustache trimmed when his son, Arak, came to tell him that their house was on fire. Instead of being panicked or flustered, as we might expect, Khosrove simply quoted his mantra and continued with his shave.
At the end of the story, when the boys return the stolen horse to John Byro, Khosrove once again quotes his famous mantra: "Pay no attention to it." It seems that nothing surprises or worries Khosrove. He is a man who lives in the moment.