What happened to Khitan race?

There is a very famous Chinese martial arts novel which features a Khitan hero. I would like to tell his story here.
The story took place in N. Song dynasty. The hero was the son of a famous Khitan warrior. When he was still a baby, his parents were ambushed and killed by Han people. He was adopted by a Han couple. When he grew up and learned his life experience, he decided to look for his own clan. In Xianmen Pass, he saw Song soldiers killing Khitan civilians and he saved these poor people. One old Khitan man tore his clothes open and showed a wolf head on his chest. Then the hero made sure of his own origin; he had a wolf head tabooed on his chest too. (Is WOLF the totem of the khitan clan?)
Then he went to the Changbai mountains in N. East China and became auquainted with Nu Zhen tribe; he even became friends with the chief of Nv Zhen. During a hunt with his Nu Zhen friends, he met Khitan people again. He took the chieftan of Nu Zhen prisoner. The chieftan admired him very much and said he would not say to anyone else except to him, the captor, which was the khitan rule. Later he released the chieftan free and even swore brothers with him. At the invitation of the chieftan, he joined the khitan tribe, his own people.
He helped his elder brother put down a riot by khitan nobles and thus granted a high office. But a few years later, his elder brother, then the king of Liao, decided to invade Song and forced him to act as the commander. He didn't want to kill Song people, who had brought him up, and couldn't resist the king's order either, so he committed suicide.