Othello - Shakespeare - Question 3, regarding Protagonist and Antagonist

The protagonist is in this story is Othello. Typically, the protagonist is considered the "good-guy." That would make Iago the antagonist. The minor characters such as Cassio and Roderigo simply are pawns in Iago's trek to take over Othello. "Well, happiness to their sheets! Come, Lieutenant, I have a stoup of wine, and there without are a brace of Cyprus gallants that would fain have a measure to the health of black Othello." (II.iii.25-27) In this case, Iago is getting Cassio in bad favor with Othello so that he may get closer to his position and cause Othello grief. Such characters reveal the character of Iago. He acts like a game master and directs them - on both sides of every argument. He is a very soothing person and can cunningly get his way. The minor characters help move along his plot. These minor characters are usually honest, which juxtaposes the "honesty" that each believes that Iago has.