Yasuo probably won't be released for League of Legends any time soon, seeing as how we haven't gotten a gameplay showcase yet. Still, Riot is teasing their way forward, the latest teaser being an animated painting that shows us just what sort of person Yasuo is.
While Yasuo the Unforgiven is viewed as a traitor to his people after supposedly killing someone quite important. Truth is, he was framed, and his life is heavy with sorrow and regret. After being framed, Yasuo has lived his life as a fugative, hunted by assassins, each of whom fell by his hand -- including his own brother.
Poor guy. He's really got nowhere left to go; except the League, of course. To check out his story and the animation, go to the official page.