Thirteen years after he's killed as the result of a raid led by his once closest friend, Wei WuXian - the YiLing Patriarch - finds himself reincarnated in the body of a tormented young man who gave his life and soul to summon him in exchange for revenge. Wei WuXian pieces together bits of the young man's life, and in fulfilling his wishes, comes back into contact with his former best friend, Jiang Cheng, and someone he'd desperately tried to befriend ever since they met twenty years earlier as students - Lan WangJi of the Gusu Lan Sect.
To Wei WuXian's dismay, Lan WangJi takes Wei WuXian back with him to the Cloud Recesses in order to protect him -- a place he visited as a student twenty years ago and wants to avoid due to its strict rules. In an attempt to get himself kicked out, Wei WuXian climbs into bed with the once modest WangJi, who shocks him by telling him to stay for the night. As they continue to spend time together solving the mystery of a demon arm that attacked Mo Village, he sees a new side to Lan WangJi and discovers that his feelings may not be -- and never were -- what Wei WuXian believed.
This is a survey of the novel, which is much richer in detail, but it's a great complement to the story! The art is pretty and I like how they're drawn in it versus the animated series (which I also love).
Mo Dao Zu Shi