Prince Li Chengqian did not die in the series. In the 23rd episode of the TV series " Celebrating Years," Prince Li Chengqian was kidnapped by Qi Heng's henchmen, but was finally rescued in time by Fan Xian and others. Therefore, Crown Prince Li Chengqian did not die in any of the episodes.
The Second Prince died in the 20th episode of the TV series " Eastern Palace." He was sentenced to death by the emperor for framing the people of Danchi, murdering Yuan, and then instigating a rebellion in the palace. In " Celebrating Years," the Second Prince's ending was suicide. After attempting to rebel, he was suppressed by Fan Xian and chose to commit suicide.