Don John is the evil bastard brother in the play. He is only recently reconciled with Don Pedro and he plays the role of a schemer, a discontent and a Machiavelli. In reality, Don John is merely the excluded character, a man who cannot fit into the society he is unwillingly a part of. When Conrad tries to tell him he should act happy around Don Pedro, he states, "I had rather be a canker in a hedge than a rose in his grace" (1.3.21-22). Don John thus ignores the family network, fails to observe the proper code of conduct, misses the dinner party thrown by Leonato, and rebels against the compulsory set of social rules.
Though Don John ostensibly influences all of the action of the play, he has very few speaking lines for a main character. Don John operates as a plot-device more than a fully fleshed out character. He does give us a little speech about how he’s a bad guy – and likes being a bad guy – but there’s not much that we say about him because we never really know his motivations, or even his reaction to all of the chaos he’s caused. In the end, he has run off before he can even be punished or have a warm, fuzzy change of heart scene. He’s definitely not Shakespeare’s most compelling and complex villain. Ultimately, though, it isn’t a failing of Shakespeare’s that this villain is so thin. It’s actually a reminder to the reader that the play isn’t supposed to be a tragedy, and isn’t even supposed to really analyze evil at all. The more important take-home points of the play are about mirth and the folly of misunderstanding.
The illegitimate brother of Don Pedro; sometimes called “the Bastard.” Don John is melancholy and sullen by nature, and he creates a dark scheme to ruin the happiness of Hero and
Claudio. He is the villain of the play; his evil actions are motivated by his envy of his brother’s social authority.
This character represents the evil part of this comedy, the dark side, the one who induces the other characters to commit erroneous actions, the one that misleads them. Therefore, the main plot is threatened by the character of Don John and his plan to ruin Claudio’s life. However, since comedies must end in a happy way, Don John’s mischief is brought to light. Therefore, it can be said that each time Don John participates in somebody else’s life in the play, we can see the dark side of them. Don John just mixes with the other characters to bring unhappiness and hatred to them. By reference to Kenneth’s Branagh’s film, it is very well portrayed what we have just mentioned, since each time Don John appears in the movie the atmosphere is darker, and he is always planning his mischievous plans in indoor spaces, compared to those outdoor spaces in which we see the other characters in the play.
He knows he is a villain and he does want to be a villain and he is going to bring unhappiness to the people surrounding him, since as he is not happy he does not want people to be happy either.
From this point of view, we could say that Don John is rather selfish because instead of being happy for the success of his brother he has no positive feeling or any affection towards his brother and the people surrounding him. On the other hand, if we get to analyse Don John’s reasons for hating his brother, we can feel some sympathy towards him, since he has been denied being a king because he is a bastard child, and that is not his fault.

Another thing that is worth mentioning is how the other characters see Don John. We have three examples in which Beatrice, Hero and Leonato talk about how Don John is. First of all Beatrice says: ‘How tartly that gentleman looks! I never can see him but I am heart-burned an hour after’.[17] Secondly, Hero responds to her and says: ‘He is of a very melancholy disposition’[18] and then Leonato says: ‘half Signor Benedick’s tongue in Count Johns’ mouth, and half Count John’s melancholy in Signor Benedick’s face’[19] implying that Don John does not talk much, in fact, he does not address to these three people in the entire play, just at the beginning when Leonato welcomes him. Moreover, the three of them agree that he has a very melancholic appearance.