Cao Zhi
At the time, Cao Cao wanted to designate an heir apparent to his dukedom (later vassal kingdom) but had difficulty choosing between two of his sons, Cao Pi and Cao Zhi. Although he favoured Cao Zhi, he knew that by custom Cao Pi should be the heir apparent because he was the older one. Huan Jie often praised Cao Pi in front of Cao Cao, saying that Cao Pi was virtuous and the eldest among Cao Cao's living sons, so he satisfied all the criteria for being the heir apparent. Whenever he talked about the succession issue, be it in a private or public setting, he always stood by Cao Pi and spoke sincerely. Cao Cao saw Huan Jie as a faithful and loyal subject so he highly respected him.