This matter was troublesome.
There were actually many unconventional methods to make someone loyal. The Gu Master world never lacked such methods. For instance, enslavement path was especially proficient in dealing with this issue.
But to turn Fang Zheng into a blood deity, these methods could not be used. A blood deity was equivalent to another life form, during the moment the transformation succeeds, all the methods used on Fang Zheng previously would lose their effects. Fang Zheng's original thoughts and intentions would influence the blood deity.
The power of a blood deity could certainly be foreseen.
Because the lightning deities derived from blood deities were extremely powerful. Vicious Lightning Fiend was only a rank six Gu Immortal, but by relying on three lightning deities, he made challenges everywhere, and his reputation kept on rising as even rank seven Gu Immortals lost to him.