In the legends of many human worlds, demon blood was the most filthy blood in the world!
Perhaps it was because demon blood contained powerful dark power and magic power. Coupled with the domineering nature of the demon genes, it often caused unknown mutations to the beings that came into contact with demon blood.
Different types of demon blood created different mutations. Based on what Roy knew, some blood, like his, could transform others into liches, and some could transform others into vampires, like Dracula. Similarly, some blood could transform creatures into demon beasts and monsters. There were even situations like the Ashan world, where humans combined with demon blood and gradually became muscular and ugly. And because of the influence of demon blood in their bodies, these mutated races were often irritable, violent, and bloodthirsty, and then they became the 'orcs' in people's mouths…
