It was really hard for superpowered human beings to upgrade after level-five. A large number of lower level zombie nuclei wouldn't be able to allow a level-five superpowered human to break into level-six. Instead, this person needed to grow his or her energy with higher-level zombie nuclei. The zombie nuclei which contained the same kind of power as the person would deliver a better effect.
For example, Yang Cheng had wind power, and was currently at the peak of level-four. He was only a breath away from level five, but he couldn't find enough energy to help him achieve a breakthrough.
Therefore, he now planned to kill Du Yuanxing and his teammates for the nucleus of the level-four wind-powered zombie. With that wind-powered zombie nucleus, he would be able to step into level-five and become a captain himself. After that, what would he need Du Yuanxing for?
