Idoneth Deepkin

When Teclis, god of light and sorcery, drew the souls of the aelven dead out of Slaanesh's long captivity, the first he remade were the Cythai: his eldest children, shaped with more hope than craft. They emerged wrong. What they had endured inside the Dark Prince had marked them: light pained their eyes, sleep returned them to the devouring, and behind every gaze their maker saw a flaw he could not mend. When the Cythai sensed Teclis's dawning horror, and guessed what a disappointed god might choose to do, they fled. Down they went, past the shorelines of the Mortal Realms, into the drowning dark of the deepest oceans, where even the gaze of gods grows dim.

The deeps hid them but did not heal them. The descendants of the Cythai, the Idoneth, soon learned the price written into their broken inheritance: most of their children are born Namarti, carrying half-souls that gutter like starved lamps and fail within a few short decades. Only a rare few are born whole. So the Idoneth made a cold arithmetic of survival: they rise from the waves in silent raids, reap the souls of coastal peoples, and carry the harvest down into the dark to be grafted onto their fading children. They tell themselves it is a tithe, not a murder. Some of them even believe it.

The Idoneth make war beneath a magic called the ethersea, a phantom ocean that their Isharann tide-priests carry with them onto dry land. Within its gloom, aelves swim through the air as through water, fangmora eels and razor-jawed sharks glide above the battlefield, and the world turns cold, muffled, and drowned. Behind the Namarti masses ride the Akhelians, the whole-souled warrior aristocracy, mounted on beasts broken to the bridle in brutal war-academies, while the Isharann bend tide, soul, and memory alike to the enclaves' need. Over all of it hangs the sign of Mathlann, dead god of the deeps: a drowned faith for a people half-convinced they are already damned.

No nation of Order is less known, because the Idoneth insist upon it. When a raid ends, the Isharann comb the memories of survivors from their skulls, leaving empty harbours, becalmed ships, and sailors' tales of a sea-mist that walks. To the surface world the Deepkin are folklore; to the gods they are a shame Teclis keeps; to themselves they are a question with no good answer: a people of Order who prey upon Order's own. Yet in the deep places there are those, High King Volturnos foremost among them, who dream that the scattered enclaves might one day stand in the light again, and be forgiven for what the dark made necessary.