He promises Ariel freedom after his next duty, but he does not free him.
One of Prospero's actions that most clearly indicates that he is manipulative is tha fact that Prospero puts Miranda to sleep with his magic so he can plan other things.
Prospero is the protagonist of William Shakespeare's play The Tempest. This character is the rightful Duke of Milan, whose usurping brother, Antonio, had put him to sea on a "rotten carcass" of a boat to die, twelve years before the play begins.
In the story, Prospero exersices control over the other chararters.
