"They have the stronger genes. Since genes are the heredity part that is made up of the DNA. As a human, we inherit our genes from our parents. But, humans are completely normal. So, when we inherit the genes, we can easily make some changes from our parents or ancestor based on our Will."
"This is also the reason why humans have the high probability to awaken the Spirit. Because our inherited Will is so weak that it can easily be dominated by a stronger Will. Unlike us, other races have a strong inherited Will in their genes. To a certain extent over inherited Will, genes and bloodlines are very similar."
"Since other races tend to inherit their ancestor's Will, they can't create their own original Will. And, if we take their genes, we also inherit their Will. Human Genes are very weak compared to other genes. So, once it enters our body, it will destroy our human genes and replace it."
