Yan does not exist in history; This is all made up. Yan is a character in the hero series. If you watch this TV series carefully, you will find that the screen goes black within one second after the opening, with the words "This story is pure fiction" in the middle, and then the TV series begins to play.
However, Yan is not entirely a virtual character, because he is the prototype of many undercover agents. Besides, TV plays exaggerate the characters. As a result, this role has become an almost invincible face we see in the play.
He is invincible, thanks to the aura given to him by the screenwriter, because he has the aura of reducing the bullet hit rate. Dozens of agents armed with submachine guns, even professional snipers, can hardly hit him. In addition, he also has an infinite bullet BUFF, and you will find that he basically didn't change the magazine when he fired.
In addition, the enemy's gun held his head many times, and he could have shot him in the head, but he was confused by his words and lost the opportunity. For example, in the game of guessing bullets, when the enemy has bullets in his hand, he never shoots. Someone finally pulled the trigger, only to find that the bullet in the gun was stolen. In short, the screenwriter is the strongest person.