Minus Wave 【負の波動 Mainasu no Hadou】 (Sai. Vol 1 - Continuous)
☆ It broke out due to the fusion of science and youkai magic, in other words the Gyuumaoh resurrection experiment; the cause of the incident. Most of the youkai feel its effects, but young children, youkai with a strong sense of self, and those who are neither human nor youkai like Goku, Gojyo and Hakkai, still retain their sense of self. There’s a large margin for individual differences. It's also noted that after the demons go out of control, they eventually regain a sense of self but see humans as food, making it impossible to go back.