Prospero is a very powerful person and using his spell books he is able to conjure up spirits and control the island though this medium. The most powerful of these spirits controls is Ariel and most of his work is done through Ariel, another example of his leadership qualities is shown in the play through Ariel as "Hast thou, spirit, Preformed to point, the tempest I bade thee". Ariel is used as an instrument by prospero in controlling and carrying out his plans.
It takes a strong, mature man to forgive those who have betrayed him and Prospero is a man who has suffered much and it seems that the time on the island has cooled his heart and is no longer the type of man who would deliver vast revenge on his enemies but instead keep them in order and forgive them as he does at the end of the play. Prospero is a puppet master throughout the play, but releases everything to save himself from his own self. In the end all Prospero wants to do is restore the balance once again but draw out the evil.
Another reason why Prospero is powerful is because of his knowledge of what is happening on the island at all times for example the plots of Caliban, Stephano, Trinculo plot to kill him and the plot to kill the kind. So when Prospero reclaims his place in Dukedom in Milan again he will have something against the conspirators just in case he needs to keep them in line or they try anything again. This way they'll think twice before going against Prospero.
Prospero also critiques his own direction, apologizing to Ferdinand for inflicting punishments upon him that may have seemed too austere “If I have austerely punished you”. This again shows an element of his leadership qualities, as he knows when he is wrong and can admit his own mistakes, this would gain him a vast amount of respect from his counter parts.
Even though Prospero deceives the shipwrecked captives, it is never for his own personal enjoyment. Instead, he specifically aims to achieve his goals by putting pressure on Alonso and restricting Caliban's scheming. It becomes obvious that Prospero has no desire to rule or lust for power to corrupt him, but only wishes a return to his previous status. Prospero is a scholar with a magic book from an entire library that so absorbed him that it was, "dukedom large enough”. Prospero displays a tinge of regret for having neglected his worldly office as Duke of Milan in favour of the life of the mind.
Prospero is a very forgiving man, because near the end of the story he forgives the two people who hurt him the most Antonio and Caliban. An example of this is when he says to Caliban "As you look to have my pardon trim it handsomely." Prospero forgives Caliban even though he tries to rape Miranda, turns against Prospero, and tries to kill him. This was especially hurtful, because Prospero raises Caliban like a son. This was probably not as hurtful as the betrayal of Prospero's brother, Antonio. Still Prospero forgives Antonio when he says "for you most wicked sir, whom to call brother would even infect my mouth I do forgive thy fault all of them". This shows his full transformation into a forgiving leader.
If Prospero was never extradited off the island he may have been a cruel leader but his time on the island has taught him a great deal about himself but about the true nature of mankind and without being powerful, caring, and forgiving Prospero might not have ever gotten off of the island. Even though he must sacrifice his magic his daughters happiness is more important then his revenge. In the end Ariel is set free as he promised. Rather than confront the "three sinners" directly, he assigns the task of telling Alonso, Antonio, and Sebastian of their need to repent, to Ariel.
We can tell that Prospero doesn’t want people to suffer as he never tortures anyone or kills anyone as he could, even though his enemies are on the island and Caliban who is plotting to kill him and raped his daughter suffers no harm. Not only does he refrain from torturing them, but also makes sure they are not uncomfortable. “our garments being drenched in the sea hold their freshness and glosses” Alonso's group includes the cheerful Gonzalo, and is never kept away from food or water. Caliban knows the island, and helps Stephan and Trinculo survive. He also makes sure Ferdinand even finds the love of his life.
