Kage Inu Yokai or Shadow Dog Demons are not as well known as the other demons of Japan but are certainly dangerous. Known more commonly as the "vampires of the demon world" they will often lose control and suck the blood of their comrades or humans.
The half-demons have two ways to becomehalf-demons. One: they could have one Kage for a parent and one human, two: a human could be bitten by one of the out of control demons. The half-demons are about as dangerous as the pure monsters themselves. This is because as a Kage Inu grows so does the thrist for blood. The higher ups in the half-demon world allow some to live discreetly, but when they lose all the humanity they have, they are exterminated.