The Abyss Peoples

Another? This is the fourteenth cargo full of gold the ambassador brought us today! Seems like those fish men harvest as if were potatoes!
— Dul Ernzuir, Imperial Minister of Foreign Affairs of Inerto.

Known also as the Lighthouse People for their bioluminiscence, for having a terrifying look, and recolecting metal and giving it away. This would be the main idea, because theres isn't much more information. Despite that, it's not too easy to ensure these are the less known of the Seven People, but I think this article will be the shortest of them. Abyss Peoples and Tide Peoples are the only two who live underwater, altough their habitats are completely different, while Tide Peoples can only live between 0 to 400 meter depth, Abyss People start to appear far below. Their origin is completely unknown; some scholars theorize they are behind widespread legends as the Laukiuro, a mythical creature from the deep sea shaped like a big snake with a shining eye on its front who guards the entrance of the Pearl Palace of the God of the Sea. They are also related with yurukula, a phenomena witnessed by some sailors in which a large area of sea starts to bright at the night for unknown reasons.

Contact

That image of Abyss People is actually quite different from legends, the first recorded contact did nothing to do with palaces of pearls or snakes. In 887 in the Second West, fifty Tide People settlers of a rock at the edge of a pit evacuated their houses after a troop of six "giants" approached from the darkness of the trench. When soldiers arrived they met with a group of denizens of the abyss inside some huge metalic diving suits. Each one of them reached around twelve meters high. Fortunately no incidents were caused, the visitors only gave the soldiers a two ton rock of iridium and then they left. Since that event they only bring huge amounts of rare metals at least twice a year, contributing to the economy of the Tide Kingdoms, in fact, the average price of gold of the Second West is the lowest of Noo. Only Tide People have contacted with them, and most of the surface inhabitants don't believe at all their existance.

Appearance

It's thought they use those strange enormous suits to protect them from the relative low pressure of the ocean at 400 meter depth, according to the resistance of the artifact it's estimated that they can live from 2000 meter depth at least, but if their technology is better than is supposed to it would mean they come from below that level. Their metalic suits only have one little window where their face can be seen. They appear to be a transparent snake with a bag at the front which has powerful bioluminiscence. The transparency of their skin allow us to see their skeleton, considerably small compared to the body. Their organs can also be seen, specially the eyes, which look like two green balls floating out of the skull. They not have any similarity with other sea species, and the skeleton looks more close to other species of the Seven Peoples than any fish or marine invertebrate creature.

Beyond that, there are only questions, it's believed they are intelligent enough to build a civilization but nobody has found evidence yet. Their language is as unknown as their technology, and the metals they bring are not easy to find neither the surface or the deep sea. They extract somehow huge amounts of platinum, gold, iridium, lead, rare earths and many other heavy metals, with unknown purposes. There is also a mystery about energy; technically deep ocean ecosystems lack of many sources of energy and thus food supplies, making the metabolism of their lifeforms very slow. But there's no explanation about how can they walk underwater with those suits that can weigh tens of tons and ascend thousands of meters carrying more tons of rocks. It's supposed they have large energy sources but there's no explanation about how they get it.