Dark Crow developed a method that allowed Black Dragon King to live for three generations of Immortal Emperors. Black Dragon King was the last disciple trained by Dark Crow and is considered to be one of his greatest disciples, who became a Taboo Existence in his own right.
Immortal Emperor Qian Li's generation
In the first generation, he trained until he reached atavism and awakened his bloodline, transforming into True Dragon. His blood had reached an extremely pure level. Even the True Dragons above the Nine Worlds wouldn't necessarily have better bloodline. This allowed him to have a unique condition. At his peak, he severed his true dragon body and only left behind a weak soul. He then moved to a new body and lived for a second generation.
Immortal Emperor Yin Tian's generation
In the second generation, Black Dragon King used his dragon soul to train an Immortal Physique. Under great effort from both him and Dark Crow, Black Dragon King cultivated the one and only Dragon Soul Immortal Physique.
At the apex of the second generation, he once again severed this Immortal Physique and left a remnant soul behind again with the help of Dark Crow. This time around, he severed it even more thoroughly. He slashed all of his bloodline and seals.
Immortal Emperor Ta Kong's generation
For the third generation, Black Dragon King started his cultivation again with Mortal Physique, Mortal Fate Palace, and Mortal Life Wheel. At the end of his life, he was able to have two Immortal Physiques at Grand Completion.
Meanwhile, the two bodies with the weaker souls were sealed by Dark Crow. He used the power of the world to nourish them and see if this would allow them to come out again. If all three bodies could come out, then he could make them represent the past, present, and future. If they could reach this level, they would be one step closer to eternal life.
There was one weakness to all of this. The three generations of Black Dragon King couldn't meet each other. This was the reason why the other two bodies were sealed.
The world knew that Black Dragon King ruled for three generations but very few were aware that the king in each one was different.
Battle vs Ta Kong
30,000 years ago, Black Dragon King and Immortal Emperor Ta Kong fought and the Heaven's Will was torn apart causing the Difficult Dao Era. After that Black Dragon King invaded the Immortal Demon Grotto and supposedly died.
Before his master regained his true body, the Black Dragon King was the only known being to have cultivated two Immortal Physiques and up to Grand Completion too. Li Qiye called this his greatest success.
Black Dragon King is a True Dragon with a supreme bloodline. This advantage allowed him to successfully cultivate a reincarnation technique created by Dark Crow. When his body reached its peak, he created a new body and move his soul to it using this technique. Nevertheless this process was not perfect and he left a residual soul in the previous body.
- Black Dragon King is one of the few beings who know that Li Qiye is the legendary Dark Crow.
- It is unknown which two Immortal Physiques he cultivated, but one of them may be Extreme Yang Physique, because a disciple from the Heaven Suppression City cultivated it later on.
- Black Dragon King is probably a descendant of Dragon God.