Read this if you confuse.

Nie Long can merge with 9 Spirit Beasts but that doesn't mean they are dead. They both become partners and become stronger together. This way he won't have to kill indiscriminately, but he still needs to kill to merge monsters to strengthen their bloodline. Below are their rank that can be upgraded.

10-19 rank = Poor potential -> Ordinary Potential.

20 -39 rank = Ordinary potential -> Good Potential

40-59 rank = Good Potential -> Excellent Potential

60-79 rank = Excellent potential -> Extraordinary Potential

80-99 rank = Extraordinary Potential -> God Potential.

Nie Long doesn't need to kill Spirit Beast for their Spirit Ring and he can make it himself. So he is like a Beast Tamer with Heavenly God Technique.