Deep Sea Demons are one of the participants in the Battle of Divine Will.
They can be found in Divine Land's 4 picture scrolls, their representative seems to be a giant eyeball with three pupils in a triangular shape also referred as The Giant Eye. Their location seems to be in the Vortex sea.
They were referred to as "Unknown civilization" before Roland's united forces of First Army, Witch Union and Taquila Witches, encountered with them in the Great Snow Mountain. They seemed to be preserving both humans and demons alike in hopes of studying them better. Demonic beasts follow their orders willingly for some reason.
The first boss level monster was encountered in the Great Snow Mountain's ruins where a DSD monster that had thousands of eyes (similar to Eye Demon) but with a wider scope where places on a ceiling. After its defeat, it separated itself and fell into water after being engulfed by a big skeleton.
From Demon's perspective Sky-sea Realm inhabitants were even more highly-evolved. From their land-engulfing ships to their most basic soldier, every one of them possessed remarkable magical power, as if they were designed just for war. Even several of the demonic beasts that they corrupted and controlled eventually grew into ones containing magical ability. Undeniably, the Sky-sea Realm was the strongest among the four races.
Zero's perspective Edit
The second painting was much more mysterious.
It had few contents, which seemed to keep moving. At least in Zero's limited number of observations, she had never seen the same scene twice. This time, she saw water. The light blue water rippled backward against three large skeletons, which were completely hollow inside, but the water was somehow held outside the bones by an invisible barrier. It was as if the giant skeletons were keels supporting the side ports, and she felt like she was in a boat and looking out through the window— except these windows spanned the entire wall.
Zero was quickly enthralled by the strange scenery in front of her... She was standing at the border between water and sky, with half of her underwater, and the other half floating above. She could see the bright sunlight and sparse clouds above her, but her legs were encased in water. Under the sun, she could clearly see the color of the water changing from light blue on the surface to bright green, and then dark green, as it went deeper and deeper. Suddenly, the scene began to shake, and Zero felt the world tremble below her and almost fell over. She subconsciously tried to open her eyes but stopped herself at the last second. "This isn't reality," she told herself. "This is God giving you a sign."
The water was quickly rising and almost drowned out the sky. Or, perhaps the water was not rising, but she was sinking downwards. Soon, everything outside the window was covered by water, and she even saw red fish swimming by the skeletons. First, there were only a few of them, but then there were more and more, and the dense schools of fish surrounded the invisible barrier like a red ribbon. The water gradually changed from dark green to a dull black, until the scene was shrouded in a complete darkness and totally disappeared.
Zero broke out of the painting, panting. This was the first time she experienced such a clear vision, and when the darkness covered her eyesight, she felt like she was about to choke. However, she did not find any useful clues—according to the secret history, the contents of the second painting were always changing. Some recorded seeing a giant eyeball, others saw a volcano spewing bubbles and yellow smoke, and others saw a bottomless abyss giving off a faint light. No observers had ever seen the same thing.
- They were originally named 'Sea Monsters' by Roland, but since the name was terrible, it was changed to Deep Sea Demons, by Scroll.