Gu Yuanli's story was really simple.
He was born and raised in Ghost City. Since he was young, he was raised very strictly by Second Old Master Gu. The brothers were all respectful to one another. As Second Old Master Gu was trying to cultivate his eldest son, Gu Yuanli was jealous of his Big Brother. Yet, he was envious of him and admired him too. He constantly tried to perform to his best around Second Old Master Gu.
Since they were young, he was the most unruly one among the brothers.
When he was twelve, Black Rose appeared. A woman who claimed to be his mother appeared and misled him about the truth regarding the death of his birth parents. She pushed all the blame to Second Old Master Gu. Black Rose still had information in Ghost City. When he was young, she purposely set him up and hid half of the story.