Qin Gu

Qin Gu (秦古) is the leader of the Yanhangmen and the sworn aide to Li Changge.

Personality
Qin Gu is a shrewd old man with years of experience under his belt. He is extremely capable in managing affairs (i.e. Yan Hang Men) and takes swift decisive action when his master is in danger. He has saved Chang Ge and Ashina Sun from trouble many times. Qin Gu is good at manipulating people to do his bidding: even Irkin Yi Nan mentioned that Qin Gu got so many Uyghur tribes to do business with him when they were reluctant with others. He often pretends to be a weak and naive old man in order to avoid trouble or suspicion, and to manipulate others, however he rarely does it for his own benefit. For example, he tricked the Great Khan, but only to help Ashina Sun get out of trouble.

History
In his heyday, under one of his previous master's orders, he started the trade route 雁行门 Yan Hang Men. It disappeared after his master died 10 years prior, but Qin Gu later revived it.

He has mentioned that he had worked under many capable leaders, all of which had been taken down by the Li family. Eventually, he came to be the aide of governor Gongsun Heng of Shuo Province.

Li Changge
Qin Gu is Chang Ge's right-hand man and key decision maker of the Yan Hang Men. He is also in charge of forging relationships with merchant convoys to expand the trade route. He is loyal to Chang Ge and has gotten her out of many a sticky situation, and even helped out Ashina Sun under her orders.

Adou
Chang Ge leaves her only disciple in Qin Gu's capable hands. He can be seen as Adou's master of sorts as he teaches Adou how to manage a convoy.

Xu Feng
They are colleagues: both serve Chang Ge.

Gongsun Yuan
Qin Gu is Gongsun Yuan's caretaker, but this job has been left to Xu Feng, who remains at their base of operations in Chang An at the moment because Qin Gu is currently travelling with Chang Ge.

Trivia

 * Characters in the manhua address Qin Gu as Qín lǎo (秦老), which translates to "elder Qin". In Chapter 36, characters took on aliases: Changge took on the alias 'Qin Lili' while Sun took on the alias 'Qin Sun'. From then on, he was referred to as "great uncle, Qin Gu". Hence it is uncertain whether Gu is his real personal name or just an alias.