I never saw the ending of Dances with Wolves was Wind in his Hair right or Kevin Costner?

What I mean is did the Sioux all get killed in the end - if they did then Costner was wrong - if they didn't then Wind in his Hair was right and his mate Kicking Bird shoudl have listened to him. And .... did the white sioux lady stay with Kicking Bird or did she stay with Kevin Costner. I reall want to know because I have tried to watch this film twice and for one reason or another my attention has been taken away from it.