Natsu Dragneel was a Normal citizen until him and the the rest of his village were attacked. They brought him back because he looked interesting.. Jude Heartfilia sent him a challenge he had to do. He was forced. If he didn't, he'd be hung. He had to fight their strongest warrior, Sting Eucliffe, until they found Erza. He then was chosen to be 'The princess's Protector.'