Yun Canghail (云沧海) is the father of Yun Qinghong and Yun Che's grandfather. After the Demon Emperors supposed capture in the Profound Sky Continent he and the rest of the high-ranking members of the Yun Family traveled there to try and rescue him, but as soon as they got over there they were trapped in the Heaven’s Might Soul Suppressing Formation, where Yun Cangahi was eventually suppressed by the Heaven's Might Soul Suppressing Formation in the Heavenly Sword Villa’s Sword Management Terrace.
Yun Che's grandfather and the very first biological family that he has ever met. He is from one of the Twelve Guardian Families that protect the ruler of the Illusory Demon Realm. Later he left the Illusory Demon Realm along with 11 Yun Family Grand Elders to the Profound Sky Continent to look for the Emperor of the Illusory Demon Realm but was chased and sealed by the Mighty Heavenly Sword Region, by the Heaven's Soul Suppressing Formation.
He was the "demon" that has been sealed within the Heavenly Sword Villa’s Sword Management Terrace, by a profound formation called the Heaven’s Might Soul Suppressing Formation. No matter who it is, in this Heaven’s Might Soul Suppressing Formation, their profound strength would be suppressed to the maximum limit. When Ling Kun stated that his son was already it made him hysterical and tried to kill someone before he was sealed again. He used some sort of gravitational pull, and ended up sucking up Xia Yuanba, causing Yun Che to sacrifice his own life to save him. He finds out that Yun Che survived his attack and waits to see how long Yun Che can survive inside the seal.
He and Yun Che spend several months together and grow pretty close to one another, like sharing food and chatting with one another, he even started sparing with him with his Profound Handle, even though he knew Yun Che's goal was to kill him so he could escape from the seal.
Yun Canghai ends up seeing the Mirror of Samsara in Yun Che's hands, which he asks Yun Che where he got it from leading to Yun Che telling him the story that his biological parents left it for him. Yun Canghai tells Yun Che that the Mirror of Samsara is the treasure that the Yun Family protects for the Demon Emperor and that he gave it to his son when they came over the the Profound Sky Continent, discovering that Yun Che could be his biological grandfather. In order to prove it they use Blood Paternity Test proving that Yun Che's is his grandson. He tells Yun Che about his parents, his families origin, and the enmity between him and the Mighty Heavenly Sword Region. He prematurely awakens Yun Che's Profound Handle.
He also handed Yun Che an unknown object wrapped in a protective white light, which he had kept hidden in his stomach, telling him to only hand it directly over to the Little Demon Empress of the Illusory Demon Realm. He also whispered a secret message that was to be repeated to her no one else. The message was not revealed in the chapter at the time, but its contents deeply startled Yun Che.
Soon afterwards, Yun Canghai severed his own heart veins, killing himself to let Yun Che escape the seal. 
After kneeling for another three days in the space underneath the Sword Management Terrace, Yun Che stored Yun Canghai's body within the Sky Poison Pearl.