XD

Ah perfect, I love smart scripts.

Hmm, do you mind if I simply keep your final edit to the sprite so I can animate it again? I'll raise your name in a disclaimer if I ever post them elsewhere again. It seems just perfect the way it is now, though I would add some grey in his groin (the chainmail that you can see in the screenshot) but since it's just the crotch there's no real need. :p Thanks.

Incidentally, is there anything else about the other sprites? Specifically Tira's (the green girl) as I think you'd have a field day fixing the mistakes in that one, I'm pretty sure it has all sorts of wrong aspects.

your sprite doesn't read easily: is that his arm off to the side or just more armour?  How is he connected to his sword

It's his arm and more armor, and if you look at the original Nightmare, his right arm is a monstrous thing, just that it can't be seen properly when most of his body is in the way. So naturally the sword is the most prominent thing on his right side. I'll agree that the lack of contrast just sorta mashes things together, yeah.

The helmet is oddly shaded and the horn has too much noise, it looks segmented and jagged.

I agree, I didn't know how to make it properly, should edit it again based on all this feedback.

Also, what was going on with your mouth?

He doesn't show a mouth, it's still his helmet. Chalk it up to poor shading, again, though it does not look like a mouth anywhere to me.

I hope this helps, what I think you need to do is focus on getting the form described more fluidly before you go crazy on the colour count

Thanks, I will. And I love criticism!

Edit:
What does Pixelation think of this? 1x and 2x.

"I think it's perfect the way it is" is not what we do on a critique forum

Sorry, I couldn't think of anything technical to add,  and very obviously I'm not well versed in pixel art, so at this point there really wasn't anything I could've said of that kind. I just formed my post based on the aesthetics as they were originally.

Anyway, I can understand right away that you contrast the colors in a very successful manner, while it did improve the sprite on a technical level, maintaining more harmonic spectrum can't be bad, since the original doesn't look in any wrong, just generally brighter; except perhaps the legs, I somewhat agree that they should be a little longer just like you drew.

Well anyway it's up to the TC to decide all this, of course, I just wouldn't pick up a dude's sprite and decide to add contrast to it, I'd rather suggest it instead, though I'm not saying you shouldn't have, as you clearly know what you're doing.

Well, fortunately I do not care for NES colors, I only made these sprites for fun.

That said, I'm in no way dismissing your criticism, it's quite educational but here I was going for making the characters resemble their fully rendered designs as simply and small as possible; in other words, keeping them as accurate as an icon can be.

That also means that I do not indend into making games with them or anything.

Anyway, I like your version of my sprite too, I definitely can see the blatant changes aesthetics that, not only makes the sprite stand out more with less definition, but still retains the basic shape, although your Soul Edge looks a bit more friendly, haha. So thanks for your post, all things considered. It really makes me glad that I am met with such a first response the moment I enter a new board, I'd never gotten it like this anywhere else. Cheers. I'll try to keep in mind your tips about the shading.