When someone comes from a navi family where everyone else is successful and praised by the clan, it always hard to live up to that status if you are seen as the family black sheep or shame. That was lo'ak life as he could never do anything right in his parents or clan eyes, as he would never be like neteyam or his sister kiri and tuk. Soon stripped of his family name and soon banished as well see as outcast by his own family and other clan, no longer a sully until he found a new place that welcome him and loved him for him.