This is pretty wonderful. You really are able to hit the nail in the head. That thing that Drifted Ashore is easily my biggest inspiration for quite a lot of the deep sea monster that roam those lands. But you hit something very important that I want to portray here, and that's community. No matter what kind of beastmen you are, all are bound together against the terrors that lurk the twilight zone of the sea.
I want to build a contrast between those terrors and the inhabitants and creatures native to creation. That is through bioluminescence, those true to creation posses all sorts of beauty and stunning color's and lights. The villages that are made in ancient sunken first age structures and around massive thermal vents are absolutely teeming with color. While the beasts born from the underworld or worse posses nothing of the sort. They are black crude monsters that give off no light or warmth.
Beyond that, a huge part of life down there is maintaining creatures similar to
Siphonophorae. Something you see quite a lot in the deep sea is these large organisms that live together communally. There is hundreds of different kinds of these! I'll just up size them a lot and say that a lot of necessary materials are farmed from such creatures.
Going further on this,
Siphonophorae are really pretty. I'm actively trying to move away from making everything be grotesque, which is how most fiction like to portray the deep. I mean just look at these things! The deep sea is very pretty in its own way.
I'm going super hard on bioluminescence being a massive part of their society. A video that shows it off in action really well is
this.
Yooooooo, shit that's gorgeous and very, very alien. I love it.
I think...hrm, I think in terms of "stuff that might be useful to consider" or "stuff that I Tenfold weirdo monster fan that I am would find interesting" that I would add to what I've already said (and lol I'm sorry for the slow reply, work's been eating my free time like it's Man vs Food):
Something to highlight might be their connection to greater Luthe. Luthe as I like to picture it was very much this massive aquatic metropolis. And when it was scuttled/assaulted by the Dragonblooded it's very likely that it broke apart as it fell. I tend to lean pretty post-post apocalypse with my Creation so some details that might be useful for flavoring is that the oldest settlements, the First Age core that the centuries of later additions grew around like coral, are boroughs of Luthe that plunged into the deeps and were scattered apart from the rest of the city some miles away (and up). And various other settlements were built in the, like, defunct mining operations and geothermal taps that used to feed the city above. The hollowed out passages and still-intact pipelines that the Deliberative left behind as they constructed the installation. It gives them a kind of shared aesthetic and history with greater Luthe while also highlighting the way they've notably diverged over the centuries and the degree to which there is (possibly sometimes fraught) distance between them.
If you want to really delve into the sense of community/shared culture some things to dig into might be just- underwater it's way easier to work vertically. Carving a relief ten stories high doesn't require a lot of elaborate scaffolding or a complex system of supports, you just have to swim up really. It's easier to build Big when you have the medium of the ocean facilitating things. And you can use that to highlight the difference between what's within and without. Beastmen cities in the Abyss are these massive, monolithic things, elaborate networks of caves and hollowed out undersea peaks, ramparts made out of oceanic mountain ranges with the tendrils and tunnels and pipes of a Deliberative-era mining facility winding through it all like some weird starfish-spider. And within the walls there's light. Literal light, light from the vents and their harvesters and tenders and the forges, light from the bio-luminescent lanterns and vast gardens of Siphonophorae, from the citizens. And the metaphorical kind: art, vast elaborate murals and carved statues and shit depicting Important Events, the Fall, the slaying of great monsters, great victories, shit that makes Mt. Rushmore look like some shitty shoestring backwater theme park. Nurseries, centers of learning, games (games are a really low key detail but one I think's pretty important honestly, "how do they play" can do a lot to humanize and flesh out a people in a narrative). The rites and rituals they have for their dead.
And then outside there's just...darkness. Darkness and the deep.
The people who live in the Abyss are very much, like, sitting at the border between two worlds. Between Greater Luthe and all it is and all it's become and all it wants to be (designs that the people in the Abyss haven't always agreed with or fit cleanly into I imagine) and the Underworld and the Labyrinth beyond. Especially when you get into shit potentially like "There's a lot of really valuable First Age ruins in the deep as well as more modern stuff from the Shogunate on that the currents carry here. Trading it is one of the Abyss's big bargaining chips with Luthe but going out and getting it is often dangerous and pretty harrowing, Luthe always wants more and the Abyss is often loath to part with the Really Good Shit they find" and "The Abyss is often on the front lines of keeping the Horrible Fucking Nightmares from slithering out and attacking Luthe directly, but Luthe only really experiences the rare fuck ups rather than the continued, constant efforts and successes".
And like I said before there's a lot of great horror stuff to sink your teeth into when you're dealing with the deep ocean. There's a lot that's beautiful there, a lot that's strange, and a lot that absolutely makes your skin crawl. And beyond that a lot that we just...don't know. And the not-knowing is often scarier than the pretty terrifying things you
do see.
Urgh, @TenfoldShields , can I use your War Crime Seals?
Sure.