Fei Jie found out who the shadow was.

Fei Jie discovered that the Shadow was Sigu Jian's younger brother.

Fei Jie discovered that the Shadow was Sigu Jian's younger brother.

Fei Jie discovered that the Shadow was Sigu Jian's younger brother. After Fei Jie removed the Shadow's mask, he saw Sigu Jian's younger brother. The Shadow was Chen Pingping's personal guard. He always wore a black mask and was cold and silent. Fei Jie had previously treated Sigu Jian's illness, so he knew his younger brother, the Shadow.

Fei Jie discovered that the Shadow was Sigu Jian's younger brother.

Fei Jie discovered that the Shadow was Sigu Jian's younger brother. After Fei Jie removed the Shadow's mask, he saw Sigu Jian's younger brother. The Shadow was Chen Pingping's personal guard. He always wore a black mask and was cold and silent. This information was confirmed in multiple documents. Thus, Fei Jie discovered that the Shadow was Sigu Jian's younger brother.

Fei Jie discovered that the Shadow was Sigu Jian's younger brother. After Fei Jie removed the Shadow's mask, he saw Sigu Jian's younger brother. The Shadow was Chen Pingping's personal guard. He always wore a black mask and was cold and silent. Fei Jie had previously treated Sigu Jian's illness, so he knew his younger brother, the Shadow.

Fei Jie discovered that the Shadow was Sigu Jian's younger brother. After Fei Jie removed the Shadow's mask, he saw Sigu Jian's younger brother. The Shadow was Chen Pingping's personal guard. He always wore a black mask and was cold and silent. This information was confirmed in multiple documents. Thus, Fei Jie discovered that the Shadow was Sigu Jian's younger brother.

The shadow Fei Jie saw was Sigu Jian's younger brother. After Fei Jie removed the Shadow's mask, he saw Sigu Jian's younger brother. The Shadow was Chen Pingping's personal guard. He always wore a black mask. Although the search results did not clearly point out the Shadow's identity, based on the discussions and the plot of the original novel, it could be inferred that the Shadow was Sigu Jian's younger brother. Sigu Jian had once killed the Shadow's entire family. Only the Shadow had escaped and had always wanted to seek revenge on Sigu Jian. Please note that the TV series may have been adapted from the original work, so the specific plot may be different.

After Fei Jie removed the Shadow's mask, he saw Sigu Jian's younger brother. The Shadow was Chen Pingping's personal guard. He always wore a black mask and was cold and silent. In the movie, the shadow faced all the rebels alone and displayed powerful martial arts.

The shadow Fei Jie saw was Sigu Jian's younger brother. The Shadow was Chen Pingping's personal guard. He always wore a black mask and was cold and silent. Fei Jie was very surprised when he took off his mask, but he didn't directly reveal the identity of the shadow. Thus, according to the information provided, the shadow Fei Jie saw was Sigu Jian's younger brother.