What illusions are presented in Act 5 of the Tempest?

There are a lot more allusions and allegory than there are illusions in act 5. Really Act 5 is where he drops the pretence of illusions and magic to address reality. Certainly we see Prospero, with his somewhat sinister studies in magic and strange powers, is a figure reminiscent of an alchemist as well, though his experiments are more involved with human nature than metallurgy.In Act 5 ,however, he asks for forgiveness and reconciliation.