Questions on A Tempest

Some questions I had about Cesaire’s “A Tempest” were, why in the end did Prospero remain on the island? He was about to return to his home with his daughter, and to regain his kingdom. And yet, he didn’t. He stayed on the island in order to make sure that Caliban was not free. Why? What is the point of this change in the play?

 

I also wondered, why didn’t Ariel return to Caliban in order to help him escape as well? He bore only good-will toward Caliban, as evidenced by his warning earlier. So why did he not return to help Caliban also become free?