Lan Wangji is the second young master of the Lan clan. Titled as Hanguang-jun (含光君), Lan Wangji is one of the Two Jades of Lan alongside his older brother, Lan Xichen. He is known for his cold, aloof and strict nature.
During his youth, he fell in love with Wei Wuxian, and mourned for him during the thirteen years of his absence. He first met Wei Wuxian at the walls of Cloud Recesses, where Wei Wuxian was sneaking in Emperor's Smile, which was banned within Cloud Recesses. The two bonded when they battled the Xuanwu in a cave after being trapped by the Wen Clan. The two stayed behind to distract the creature while the others escaped to call for backup. It was in the cave when Lan Wangji first performed the song WangXian to Wei Wuxian when the latter was weak after being injured by the creature.
When Wei Wuxian became the Yiling Patriarch, he often tried to persuade him to stop following the dark arts and attempted to protect him from being persecuted by the other cultivation clans, but to no avail. During the First Siege of the Burial Mounds, he tried the protect Wei Wuxian and in the process injured 33 of his clansmen. After the battle, he was punished to receive 33 whips and was grounded for 3 years, which he spent recovering from his punishment. During the 3-year period he heard of Wei Wuxian's death and despite his injuries, rushed to the Burial Mounds to look for him. Although he was unable to find anything related to Wei Wuxian, he found Wen Yuan, suffering from a fever, hidden away in a hollowed out tree.
Lan Wangji was the first to recognize Wei Wuxian in the body of Mo Xuanyu when Wei Wuxian played the song Wangxian to summon Wen Ning.
