Okay, I've got some good news and some bad news.
Oceania's limitation of "only turtle-crap in land forts" is apparently pretty hard-coded. I cannot add any new recruitables to Oceanian land castles. So, the Dema alliance is out of the picture. Well, I re-read this thread and the Oceania suggestion thread for some ideas and then started working.
One thing that has always bothered me a bit in EA Oceania is that there are Triton Kings, but where are the queens. Oceania is a total sausagefest anyways. I thought about just giving some queens as summons, but they would be N/W anyways, and thus not very useful. I scrapped the idea, and but in the selphies, since Honeybadger was nice enough to give a graphic for the sea form!
Then I went for a different route with the land castle problem. If turtle infantry is all that you get, it needs to be sexier. So I replaced the turtle guys with a "Daughter of Selphie" (magepriest) and "Son of Selphie" (troop), which introduce the "mist bringer" themes of Chrispedersen.
Then I got a another idea for the queens when brainstorming descriptions for the selphies.
Oceania was once truly the kings of the sea. Knowing that they'd never be able to conquer the dry realm above the waves, the ancient "uber" Triton Kings (hinted in the description of vanilla Triton Kings), devised a plan to start a great flood and to make the world theirs. However, Pantakrator found out about this and stripped the Kings of much of their powers and cursed the triton queens with hideous bodies (inspired by the legend of scylla). Ta-daa! Late-game monsterous summon!
Since picture is worth a thousand words...
a) Daughter of Selphie's land form. She'll be A1W1H1 (with A/N/E/W random).
b) Daughter of Selphie's water form. Nothing special planned about it.
c) Selkie's land form. I'm going to farther away from the myths a bit and make them tricksy and curious water/mist spirits with good access to air to introduce the mist theme. They'll swap the air magic for water in sea. The Selkies have made a strange deal with Oceanian people... (I'll expalin in detail once I've figured out some details)
d) Son of Selkie's water from. Underwater, these guys won't do much. I might give them animalawe to give them a niche use UW against shark spam.
e) Son of Selkie's land form. These will be okay troops with glamour (granted to them by the magical otter-skin cloaks grafted to them by their mothers)
f) Cursed Queen - These will be a late-game summon. When the queens got mutated by Pantakrator, they couldn't stand it, and fled to the deeps. With aoens, they've taken to witchy practices in a futile attemp to get their old bodies back. They will grant small access to astral/death. Probably W2N2 with 100% for either S2 or D2. The lower part of the picture got somehow corrupted when I copy-pasted it.
g) Uncorrupted Queen - She will be a hero. She is uncursed because she was the one who told the pantakrator about the flooding plan. Hence, she didn't get the curse, but had to flee the wrath of Triton Kings. Compassionate soul, she will be a mighty healer and nature mage.
h) Seal, the water form of selkie.
i) The Dema Troops I managed to make before I found the full scale of the land castle problem, these will not be feautred, but since I made them, I just might as well show them off.