This started off as a random sketch and turned into a random painting.
Notice I even labeled it "random sketch" just to be absolutely certain that I didn't up and decide that it was a not random sketch, because...whoa, that would be very bad, somehow, I'm sure.
Much of the time I leave my random sketches alone to go work on the non-random ones, but the guy on the right clearly wanted to fight something. I decided that it was to be a scene that could take place in the Mistborn Trilogy, by Brandon Sanderson. And then I just kept on going to see where it went. The girl is Vin, the main character, and I'm not sure who the guy with the knife is. By the way, if you haven't by chance heard of the Mistborn books, you might want to give them a look. Excellent world building, and more importantly, excellent characters.