The content of the last episode of the first season of Qingyu Nian was Fan Xian bringing Yan Bingyun back to Northern Qi and appearing together with Shen Zhong, Ye Qingmei, and the others. Fan Xian and Shen Zhong engaged in a fierce battle. In the end, Shen Zhong was subdued and surrendered. In this episode, some secrets regarding the Ming family and the Qing Emperor were revealed. In the end, the Qing Emperor was heavily injured by Fan Xian. His left shoulder was shattered by Wu Zhu, his abdomen bled, and his left arm was broken by Ruoruo. Even though the Qing Emperor was about to die, he thought he had won because Fan Xian had appeared and been crippled by him. The Qing Emperor had even crippled Wu Zhu. No one present could threaten him anymore. Fan Xian was conferred the title of Imperial College's official, but in reality, he had fallen into the Qing Emperor's trap. In the end, the Qing Emperor died. Fan Xian and the Qing Emperor began a battle of fate.
I'm not sure which novel you're referring to, the last episode of the second season, and what '11' you're referring to. If you can provide more information, I will try my best to answer your questions.
In the last episode of the fourth season, episode 20, Wang Nima said,"We don't need to be perfect. We just need to keep improving and moving forward." Even if we fail, we should learn to learn from it and continue to grow." This sentence expressed Wang Nima's attitude towards the team's progress and growth. At the same time, he also called on the team members to remain optimistic and courageous in the face of challenges and failures.
Well, without having read it specifically, I can only guess. But generally in the Airbender world, it's a place full of elemental powers. So this novel might tell the story of the last airbender's struggle. It could be about their fight against the forces that are disrupting the balance in the world. They might be on a quest to find other airbenders who might still be alive, or to master all the airbending skills to become a true savior of their world.