The monstrous beasts killed during the task could still increase one's cultivation. There were countless monstrous beasts in the stone ocean and demon forest. For them, it was equivalent to a rare hunting ground. Once a human practitioner's cultivation reached their normal level, the number of monstrous beasts that they had to kill if they wanted to improve further was too many.
With Mo Wen's current cultivation, if he wanted to step forward and reach the later stage of the Golden Elixir Realm, he needed the power of starlight. He would need the total sum of the power of starlight that he had collected up until now. It could be said that only with the power from killing four Beast Kings could he possibly go up a rank.
Also, even if Mo Wen reached the later stage of the Golden Elixir Realm, his Inner Qi cultivation still could not compare to that of a Martial Arts Grandmaster.
