Auron was Guardian, bodyguard, to High Summoner Braska on his pilgrimage to wipe out the giant monster known as Sin along with a man named Jecht. Braska died shortly after his pilgrimage and Jecht was never seen again however Auron, worried about both men's children arranged for them to be taken care of. Auron arranged for his friend Kimahri to go and take care to Braska's duaghter, Yuna, while he went to take care of Jecht's son, Tidus, himself. Ten years after Braskas pilgrimage Auron notices that Sin is again active and appears in Zanarkand, Jecht and Tidus's home city. Auron knew how to use Sin to cross between world from Zanarkand's to his home world of Spira and is certain Jecht would want Tidus to go there so arranged to travel with Tidus to Spira. Though Tidus and Auron arrive separately in Spira, Auron eventually finds him. By the time Auron is met again in game Tidus has met and joined Yuna as a Guardian on her pilgrimage. Auron asks to join as well to keep an eye on both Yuna and Tidus. Upon remeeting Tidus Auron reveals that Jecht has become Sin and they are on thier way to kill him. Why or how Jwcht became Sin Auron is hesitant to speak of and instead tells Tidus he will find out at the end of the pilgrimage. It is Auron's desire to kill his friend putting him out of his misery and help honor Braska's legacy by helping Yuna undertake her own pilgrimage. Over the course of the game more and more clues are dropped that Auron is an "Unsent" the equivalent of being undead.