Genetics...
That is what many races chase after every single day of their lives.
It was believed that with good genetics (body, bloodlin, bones...) and whatever else makes a person whole, their race would never decline but only improve with each generation.
There are many races out there known as hybrid races because they are a combination of two different breeds. There are even tri-brids and those with four, five, and more combinations of DNA.
The demi-human race is a typical example of such a race. Their original genetics aren't good enough to handle the rising demand of the cultivation world, so they tend to strengthen them using all kinds of methods.
Not that they are to be blamed for that. Most are merely chasing after greatness, a chance to stand at the peak... among the immortals and gods.
So, using unorthodox methods to achieve it is not something to be disgusted by. However, those with good genetics, of course, see themselves as superior.
