Disclaimer: I do not own Lion King, only borrowing the characters and some of the dialogue.
"Sometimes what's left behind can grow better than the generation before, if given the chance." Simba said as he pulled his paw through some dirt to reveal a sprout. Kovu watched intently, Simba had just finished telling him, his version of Scar's story and Kovu was inclined to believe him, after all Simba hadn't seemed like the type of lion his mother had made him out to be. They were quickly interrupted by the sound of evil laughing, both lions looked up in alarm.
"Zira." Simba said as the lioness came into view.
"Why Simba, what are you doing all the way out here and so alone." Zira said as the lions approached both Simba and Kovu, both lions started growling respectively. Simba was slightly shocked by this. As soon as he had heard Zira's voice he had expected Kovu to join her. Maybe he really didn't want to be a part of her pride anymore. With this thought in mind he decided that he would have to ignore anything Zira said about Kovu during the battle and keep an eye on him out of the corner of his eye, and with that the battle commenced. He kept half an eye on Kovu the whole fight and watched as Kovu appeared to have his back. As the lionesses tried to reach him, Kovu would attempt to fight them off before they could. It made it a lot easier for Simba to keep his attention in the front of him and not have to worry about and lionesses attacking him from behind. As the battle wore on the two lions began to tire and soon found themselves nearly surrounded, by a bunch of logs on one side and by lions and lionesses on the other.
"Kovu. How dare you betray me? I thought you wanted the same thing I did. Revenge." Zira said. Simba realized that he had been right about Kovu in the beginning but that Kovu was now a lion that he could trust no matter what came out of Kovu's mouth next.
"While I may have originally wanted the same things mother, meeting Kiara and Simba, and learning the true story of Scar. I realized that you were wrong about everything. I have made my choice. I will fight to protect Simba, Nala, and Kiara until my last breath." Kovu said.
"So be it." Zira said as they circle moved to close in on the two of them. Simba looked at Kovu and nodded his head towards the logs. Immediately understanding, Kovu moved with Simba as the two of them moved up the logs as fast as they could. The rocks were unstable though and started to fall, he heard one fall and hit a lion but couldn't be bothered to see whom. Simba made it to the top before him and when Kovu started to slip, Simba aided him much to Kovu's surprise. The two lions looked down to see Zira frantically pushing the logs aside and Kovu realized who must have been the lion who was hit by the log, Nuka. Kovu felt a moment of grief for the lion he once called brother but was immediately distracted by the grunt of pain coming from Simba. He ran over and helped to support Simba as the two lions slowly made their way to Pride Rock. As the came into sight of the place he hoped he could still call home, the warthog and meerkat—he couldn't remember their names, came to help him get Simba up to the cave.
"Simba, what happened?" Nala asked as they got to the top of the rock and Simba laid down to rest.
"We were ambushed by Zira and the rest of the Outlanders, if it wasn't for Kovu I probably wouldn't have made it back. Thank You, Kovu." Simba said.
Because of Kovu proving himself to Simba, he was never exiled and walked beside Simba to battle his family. During the fight, Kiara finally understood what her father had told her all those years ago, 'We are one; and managed to get the other lionesses from his old pride to switch sides as well. Zira, not ready to give up on her revenge attacked by herself, but was quickly outnumbered and killed. Kovu was surprised to find that he didn't feel all that sad about losing his mother. Both the Pridelanders and the Outlanders returned to Pride Rock, where he and Kiara were wed and would one day take over the kingdom.