Gian Maria Volonté as Ramon Rojo is perfect. He reflects the evil while TMWNN reflects the not so bad. I can't really say good because he does his fair share of killing too.
Volonté gives a terrific performance, he shows how money and greed can turn a man. The last scene is excellent. His eyes say it all, his wonder at what is happening when he keeps firing and TMWNN does not die. Leone chose two actors (Clint and Volonté ) who together sum up the essence of the movie.