In a world plagued by an abomination--Sin, people struggle to live lives where they can sleep peacefully in beds at night, and that they don't have to worry about Sin appearing anytime. That's where Summoners come in. Summoners are people who obtain the trust of fayths--victims of Sin who are trapped in stone statues--and are entrusted powerful creatures which aid them in their journey. Summoners summon the Final Aeon after obtaining enough aeons and undergone enough training...to defeat Sin