As a devil incarnate, why did Cheng lose his reputation in his later years?

Cheng's title of "Demon on Earth" was given by an old bull's nose, and it was a joking title in the Romance of Sui and Tang Dynasties. Cheng is a lucky general who firmly supports the armed forces to seize power. After the coup, Li Shimin did not mistreat him, and the hero of Lingyange surpassed Qin Qiong. It is such a lucky general, why is his old age so bleak?

It is still a very depressing thing to say. The half-life hero of the army also made mistakes in his thoughts.

During a crusade against West Turkistan, the two armies fought and eventually the West Turkistan was defeated. A lieutenant named Wang cheated Cheng because he was jealous of Cheng's contribution. At this time, it is not appropriate to chase the defeated soldiers and let our soldiers slow down and chase the deserters. What is even more outrageous is that Wang lied that he had obtained the imperial edict and asked Cheng Jun to give it to Wang himself.

Cheng Xin, don't listen to the advice of lieutenant Su Ding. When Tang Jun arrived in the city, facing the surrendered conference semifinals, Cheng listened to Wang's slanders and began to slaughter and plunder money. To make matters worse, after Banshi returned to South Korea, he pretended to be a beheading soldier and took the meritorious military service.

After Banshi returned to Chaoxian, Wang's imperial edict and private division were exposed and killed. The court investigated Cheng's responsibility, but Cheng refused to share the spoils. Finally, the court decided to remove Cheng from his post because he didn't stay and didn't try to catch up with the enemy.

This is a shame. Although he was later activated by the emperor, Cheng was over 70 years old, no longer attached to fame, and resigned and went home. In the second year of Linde (665), Cheng died of illness at the age of 77. Li Zhi sent a memorial to the general, a title of generals in ancient times, the governor of Yizhou, and posthumous title. Buried with Zhaoling. It is relatively complete!