I'm sure he does have other targets. His primary motivation, aside from straight up psychosis, is showing the "strong" people what "true power" is. He's clearly just looking to be renowned/feared/legendary ect. His very public show he made in the beginning is evidence of that. How he chooses the order he takes them, if he even does, is a mystery. He may just take them when he has the opportunity. Then again going by previous events i'm not even sure why he's entering the tournament to begin with. He killed the first guy simply by firing at the screen of a live feed, so why the hell isn't he just standing with the spectators busting off shots at every screen in front of the crowd so they can watch them magically keel over one by one?

None of it makes a great deal of sense, but that's just fine i'm just here for the cool fight scenes anyway.