how does iago plan to use his dupe again for his own ends

Iago claims to know nothing of the battle between Cassio and Roderigo. He says he has merely discovered it, although he is in fact the mastermind of the entire situation. Once again, Othello, his dupe, accepts his explanation. Iago is many selves in this act; he is friend and advisor to Roderigo, then betrayer and murderer of Roderigo, consoler of Cassio, and the lead officer in this crisis. He uses misrepresentation to fill each of these roles as best he can, and not let the others know of his true plans and character.