Iago's keen intellect is what intrigues the reader most. His ability to say the right things at the right time is what makes him such a successful villain. However, someone with a conscience would never be able to keep up such a ploy and deceive everyone around him. This is why it is necessary to say that Iago is amoral, because if you don't his character becomes fictional and hard to believe. Iago is not your ordinary villain. The role he plays is rather unique and complex, far from what one might expect. Iago is smart. He is an expert judge of people and their characters and uses this to his advantage. For example, he knows Roderigo is in love with Desdemona and figures that he would do anything to have her as his own. Iago says about Roderigo, "Thus do I ever make my fool my purse." [Act I, Scene III, Line 383] By playing on his hopes, Iago is able to swindle money and jewels from Roderigo, making himself a substantial profit, while using Roderigo to forward his other goals. He also thinks quickly and is able to improvise whenever something unexpected occurs. When Cassio takes hold of Desdemona's hand before the arrival of the Moor Othello, Iago says, "With as little a web as this will I ensnare as great a fly as Cassio." [Act II, Scene I, Line 168] His cunning and craftiness make him a truly dastardly villain indeed. Cassio, like Roderigo, follows Iago blindly, thinking the whole time that Iago is trying to help him. And during this whole time, Iago is planning the demise of Cassio, his supposed friend. On the night of Cassio's watch, Iago convinces him to take another drink, knowing very well that it will make him very drunk. Iago sets Cassio up to get fired. .
At the climactic ending of the play, Iago's plot is given away to Othello by his own wife, Emilia. Iago sees his wife as an obstacle and a nuisance so he kills her. He kills her not as much out of anger but for pragmatic reasons.