Sting Westclaw was banished from his homeland after robbing dozens of banks and taverns. He's found a new home in the desert area of the Post-Apocalypic Wastelands. There's not much to steal there, but he has all the money from his robberies, his guns, and enviable aim. He'll be fine.
"Do I feel lucky?" is a famous line of dialogue from the movie Dirty Harry. While "Make my day" is another line from the 4th Dirty Harry movie, Sudden Impact. "Get three coffins ready" is a line the Man with No Name gives in A Fistful of Dollars.
"It's High Noon" is a reference to the ultimate ability of Overwatch character McCree (whose design is also inspired by the Man with No Name).