In "Chen Qing Ling", Wei Wuxian's dark revenge was in episodes 19 and 20. Wei Wuxian was thrown into a mass grave by Wen Chao. A few months later, Wei Wuxian was buried in a mass grave. When Gang came back and became a ghost, the first thing he did was seek revenge against Wen Chao and Wang Lingjiao.
We cannot say here that Wei Wuxian is a black man. After all, he did not kill innocent people indiscriminately. He killed Wen Chao, Wang Lingjiao, and Wen Zhuliu. The pain is eternal, and it is difficult for Wei Wuxian to understand the hatred in his heart without crushing Wen Chao to his bones and turning him into ashes. In the novel, Wei Wuxian struggled in the mass graves for several months. He was swallowed up by resentment and tortured, but he was still thinking about revenge and Mrs. Yu's words about protecting Jiang Cheng even if he died, so He can't die now because he still wants revenge and protects Jiang Cheng and his senior sister.
After Wei Wuxian came back, both Wang Lingjiao and Wen Chao got their due retribution. In the original work, Wei Wuxian made Wang Lingjiao eat the stool legs and cut off Wen Chao's hands and feet. He also tortured Wen Chao to a state of disgrace. Although Wen Zhuliu escaped with Wen Chao, he still could not escape the torture of Wei Wuxian and his brats. Ever since Wei Wuxian came back, he was no longer the bright young man he once was, and his eyes had lost their color. He was destined to live as the ancestor of Yiling.