Almost none of Cao Cao's descendants were Emperors, and each of them was excellent. Cao Pi, Cao Rui, Cao Fang, Cao Xian. However, in the era of Cao Fang, it was already controlled by Sima Shi. In the era of Cao Xian, Sima Zhao's heart was well known. Cao Xian was also a bloody teenager, and he was not willing to be a puppet, so why didn't he arrange a knife and axe hand when Sima Zhao met him and kill him alone. But with hundreds of guards behind them fighting to the death? Let's analyze it.
One: Cao's behavior is closely monitored
I think that in that year, Cao Cao put Emperor Xian of Han in the air, and what Emperor Xiandi of Han did was clearly known to Cao Cao. Now that the feng shui took turns, Cao Xian's every move was clearly known to Sima Zhao. Cao Xian did not learn to be patient, and as soon as he succeeded to the throne, he showed great wisdom and was a mingjun approach to the hundred officials and the people. But it was too early to do so, and Sima Zhao's men saw the little emperor's ambitions, so they monitored his every move together. As long as it's not too much, they'll let Cao Fu do it! It was impossible for Cao Xian to arrange any knife and axe hands, after all, people were all controlled.
Second: Cao Xian wants to single out Sima Zhao, and it is estimated that he will not win the fight
Even if Sima Zhao visited Emperor Cao Zhao alone, Cao Zhao was not sure of winning the battle against Sima Zhao. After all, Sima Zhao's two brothers had followed Sima Yi through the battlefield for a long time, and the value of force was very high. Cao Xian was living in the deep palace, and he was very young at that time, not yet 20 years old. Can a guy under 20 beat a battle-hardened player? I don't think so! Moreover, if Cao Xian did this, after the failure, there would really be no drama. Therefore, Cao Xian will not do this unless he has to.
Three: Cao Fang is a lesson from the past
Before Cao Fang, Cao Fang was a puppet of Sima Shi, so Sima Shi could control Cao Fang by controlling Cao Fang. With Cao Fang's previous experience, Cao Xian had to be cautious, they were also puppets, so Cao Xian had to find a way to get rid of control, so he was forced not to be so impulsive. Sima Shi would not let him get out of control so easily!
Fourth: It is imperative for Sima Zhao to usurp the throne
If he could make Cao Xian live for an extra ten years, then he could kill Sima Zhao! But Sima Zhao was such an old fox that even the famous generals Deng Ai and Zhong Hui were toyed with by him. Cao's tricks can hide from him! Therefore, Sima Zhao was very opportunistic, and when Cao Xian was 19 years old, he wanted to add the title of Duke of Jin, and he also added Jiu Xi and the story of Cao Cao that year. This is the rhythm of usurpation! So Cao Xian, with some bodyguards and cronies, added up to several hundred people attacked Sima Zhao's mansion. Of course, this battle was tantamount to hitting a stone with an egg, and Sima Zhao quickly pressed Cao Huan to the ground and rubbed it, and Cao Xian's death awakened many people who supported Cao Shi. Therefore, the usurpation of the throne by Sima Shi was delayed for 4 years.
To sum up: Cao Cao's descendants are still bloody and have not disgraced Cao Cao. However, Sima Shi was too cunning and usurped Cao Wei's Jiangshan!
References: Romance of the Three Kingdoms, Book of Jin