Basically the sully family left home to the metkayina clan and Neteyam found a certain boy amusing and pretty the chiefs son Ao'nung

I am Neteyams #1 fan and i looooove Aonung so i thought, why not make them love rivals? Also i'm not going 100% by the movie events, some things that occur in the movie might not happen in this, but no promises;) -- Ayturi has always known she would become a mated pair with the Metkayina Chief's son, Aonung. It was her greatest happiness as a child, to love him and follow him around, the mighty warrior she would one day call her own. And yet, Aonung always looked at her like some kid he just couldn't shake. As Ayturi got older, she began to realize just how little Aonung cared for her- how little he wanted her as his mate. Just when she feels she should give up, the Metkayina leaders and her parents announce the betrothal of Ayturi and Aonung. But there's no time to talk about it, to see how Aonung will react. Because moments after the announcement is made, outsiders arrive on the island. The news of their betrothal is swept under the rug as they are given the task of teaching the newcomers their ways. But as the eldest son of Toruk Makto begin's to catch Ayturi's attention, how will Aonung react?