yeah but i dont think you can deny that his heart makes him the TYPE of fighter and person he is. if we look at shikamaru for exmaple he would never have dont anything at all if he had the kyubi in him. while i certainly think its why he is as good as he is, i still think hed be decent without it (didnt jira or ebisu say it was hard for him because the kyubi chakra didnt mix well or correct wiht narutos own? thus making it more difficult to mold it).