The Shuuki (醜鬼), meaning "Vile Demons," are the primary antagonistic creatures in the manga and anime series Mato Seihei no Slave (Chained Soldier). Emerging from the mysterious alternate dimension known as Mato, the Shuuki are monstrous entities that pose an existential threat to humanity. Their terrifying presence prompted the formation of elite military units composed mainly of women who have gained supernatural powers from special fruits called Peaches. These monstrous beings are highly dangerous, come in various forms, and are central to the conflict within the series.
Description[]
Shuuki are generally feral and extremely aggressive, attacking any human on sight. They seem to operate on primal instincts, drawn to violence and destruction. However, as the series progresses, it’s revealed that not all Shuuki are purely mindless beasts— Hachiraishin, which are the most powerful Shuuki who refer themselves as "gods", show signs of sentience, planning, and complex communication.
Their motivations appear rooted in a desire to conquer or dominate the human world, suggesting a deeper, more strategic element to their invasions. They are territorial, fiercely defensive of the Mato world, and seem aware of the growing threat posed by empowered humans—especially the Anti-Demon Corps.
Shuuki, in general, are taller than an average adult male with numerous shapes and builds, mostly having an almost dark skin tone and texture that resembles raw muscles while their faces are pure white in color, having a misshaped face appearing to resemble a grotesque mask. They have monstrous features ranging from darker skin tones to exposed bones and multiple eyes and arms.