THOR! aka The Mighty Thor

Thor's home planet is Asgard, his step brother is Loki which is also his enemy. 
Thor was too proud to be the king of Norse gods so he father Odin sent him to earth as punishment and told him to live as a normal human and until he learned how to be humble he would have to stay among the human race. As an even worse punishment king Odin erased Thor's memory, so he was living on earth believing his name was Donald Blake and he was putting himself through medical school. After a while King Odin realised how mature his son had grown so he returned Thor's memory and even gave him the Mighty Mjolnir, the mighty hammer. This allows Thor to call down lightning and wind from skies above. Since Thor now had something he could use to fight crime he decided to stay on Earth and fight evil.