False Nascent Soul! Just like the false core Wu Qi formed in his dantian previously, it was a trick found in Scroll of Stealing that was used to deceive and mislead outsiders.
By using White Cloud Immortal Sect's Energy Unity Script as the foundation, on absorbing an enormous amount of energies and filling his Gold Core with Immortal Chang Wu's Heavenly Dao enlightenment, Wu Qi eventually formed this false Nascent Soul with the mystic technique. It contained all of Immortal Chang Wu's Heavenly Dao enlightenment of the Heaven Immortal grade. As long as Wu Qi could comprehend all of them, he could then push his cultivation base to Heaven Immortal realm with this false Nascent Soul.
