Champion, Terence Blanchard's new work at the Metropolitan Opera, has been getting a lot of press lately. It's the first opera about a boxer, with bass-baritone Ryan Speedo Green in the lead as the ill-fated welterweight champion, Emile Griffith. But the themes are less about pugilism and more about universal human experiences of guilt, forgiveness, and compassion. Three dimensions of Griffith are revealed as this gr…