I didn't like how they portrayed her in the series; in the story, she's nothing like that.
The true villain of the story is Xie Yanfang. As for Deng Yi, he was initially on Xiao Xun's side, but later switched to Chu Zhao's side. At one point, he has a falling out with Chu Zhao, and Xie Yanfang takes advantage of this to try to kill him. However, Xiao Xun saves him, and they flee the capital to Xiao Xun's house. There, they attempt a rebellion, but Chu Zhao manages to quell it, and Yanlai kills Xiao Xun. Deng Yi is hit by an arrow from Chu Zhao, but does not die. By this time, she already suspects Xie Yanfang, so she fakes Deng Yi's death along with Xie Yanlai and sends them to live with her mother, who in the story is alive and is a mountain bandit. She returns to the capital and keeps an eye on Xie Yanfang, planning to keep him prisoner. However, things go wrong because he discovers that she has a mother and that she planned to leave, which he doesn't want. He ends up liking her, but doesn't show it, only wanting to keep her close. His plan fails, and Yanfang tries to kill Chu Zhao's mother's men and force her to stay in the capital. Xie Yanlai returns in time and saves Chu Zhao. A fight ensues, and Xie Yanfang is seriously wounded. Chu Zhao leaves with her mother, and Xie Yanlai returns to the capital to stop Yanfang from trying anything. Some time passes, and she decides to return and take the throne with the help of Deng Yi, her mother, and her father's army. In the end, Yanfang dies, Xiao Yu continues as emperor, and she goes to the border to live with Yanlai, where they even have a daughter.
Since The Blood of Youth is on the list, if you're going to watch it, also watch the other two dramas from the same universe, in chronological order: Dashing Youth Blood River The Blood of Youth
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As for Deng Yi, he was initially on Xiao Xun's side, but later switched to Chu Zhao's side. At one point, he has a falling out with Chu Zhao, and Xie Yanfang takes advantage of this to try to kill him. However, Xiao Xun saves him, and they flee the capital to Xiao Xun's house. There, they attempt a rebellion, but Chu Zhao manages to quell it, and Yanlai kills Xiao Xun. Deng Yi is hit by an arrow from Chu Zhao, but does not die. By this time, she already suspects Xie Yanfang, so she fakes Deng Yi's death along with Xie Yanlai and sends them to live with her mother, who in the story is alive and is a mountain bandit. She returns to the capital and keeps an eye on Xie Yanfang, planning to keep him prisoner. However, things go wrong because he discovers that she has a mother and that she planned to leave, which he doesn't want. He ends up liking her, but doesn't show it, only wanting to keep her close. His plan fails, and Yanfang tries to kill Chu Zhao's mother's men and force her to stay in the capital. Xie Yanlai returns in time and saves Chu Zhao. A fight ensues, and Xie Yanfang is seriously wounded. Chu Zhao leaves with her mother, and Xie Yanlai returns to the capital to stop Yanfang from trying anything. Some time passes, and she decides to return and take the throne with the help of Deng Yi, her mother, and her father's army. In the end, Yanfang dies, Xiao Yu continues as emperor, and she goes to the border to live with Yanlai, where they even have a daughter.
Dashing Youth
Blood River
The Blood of Youth