Question: how is kovu related to scar?
Answer: Kovu is claimed to be the youngest son of Zira, who is a close follower of Scar; his two older siblings are Nuka and Vitani. He was apparently born at some point during Scar's reign, as Scar hand-picked him to be his successor. As a result, he was referred to by the Outsiders as the Chosen One.