Ha when I found Ina I was questioning my sanity, now seeing your pfp it makes sense. I’ve just got to ask, and maybe it will be answered when I get further in, would she be somehow connected to that abyssal corruption bar in the future. I totally get it if that isn’t connected to your vision for the game, I just thought it was interesting along with the eldritch sound of some things like the description of the insight stat, thanks for all the hard work.
Ina's name is definitely a bit of homage to our priestess, but that's as far as I went - anything more and it starts lurching too close to plagiarism. So no abyssal relation with her, and she won't be a priestess of the old ones.
Other characters may end up closer to that niche though, I do think Hololive Ina's design is fantastic and something along those lines could work in the setting! Just not obviously Ina.
Abyssal will get its own, hopefully unique stuff - though the Lovecraftian vibes aren't too subtle I admit!
Battle-fook systems are wily beasts, especially when combined with situations that call for lethal force. Mind, I suppose that a bit of eromancy to...distract...an enemy could leave them open to a fatal blow.
Speaking of Ero-battles, you might want to check out Monster Girl Dreams on Itch. I suspect that you and most fans of Divine Dawn would enjoy that one, what with being text-heavy and usually light-hearted. That particular game made it law of reality that genuine harm cannot be dealt between people. That makes sex the way to resolve conflict.