I'm not sure if you're wanting artistic advice, but I'm going to say this anyway because I was thinking about this a while back so I have some ideas.
Standard caveats apply: your model, you can do what you want with it, just providing input.
Okay, so. The point of this is to increase the model's fidelity, but if you just take the same overall shape and add a lot of surface detail, it'll probably end up looking sort of...delicate? in a way that might not suit the Demon. So I think the best approach would be to reimagine the morphology somewhat.
IIRC, Battuta once, during a previous discussion of this topic, described the Demon as something along the lines of "a big fat spider that sits out in space bleeding fighters". With that imagery, combined with bits of the HTL Rakshasa, I think I have a hook that might give you a way to make a strong artistic improvement.
So, I think the key to the Demon's overall appearance is these...ribs? Legs? I don't know what you'd call them.
As it is, they're very blocky. What if they were much smoother? Like big fat spider legs. Or, say, like these spikes on the side of the Rakshasa:
If you round off the "legs", make them into tapered cylinders running halfway up the model -- then gradually make the curve more gentle the higher you go -- you'll end up with the flanks of the ship having this wavy, rib-like structure, with crests and troughs. This ought to result in a somewhat organic feel -- almost a little Gigeresque -- that I think will suit the Shivans well.
Also, one other thing:
I kind of think you should maybe round off that corner. It's weirdly square and I don't think it looks good. I'm a lot less sure about this one than I am about the ribs thing, though (and the extra-pointy the WIP has it kind of works in its own right), so if anyone else feels differently please chime in.
Overall: as it is, you're rounding off some parts of the model but leaving a lot of sharp angles in. I think you're at risk of making the Demon look very high-tech, which I don't think is really appropriate. Obviously the Shivans are
high-tech, but that doesn't generally come across in their visual design -- their ships don't look advanced; they look eldritch and animalistic.
Anyway, those are my two cents. Hope you'll get something useful out of it, but if you don't, oh well.