OK, since a few people said they don't mind long walls of text, I will happily oblige with some reasoning and other obscure details about my Fighting Spirit design. So here goes...
I really wanted to get away from the human form. But, when dealing with ghosts, I found it almost impossible to avoid. Yes, there are things like Spiritomb, Duskull, and Haunter. But, most concepts of "dead", really mean "dead human". When I decided to go with a Tribal/Djinni theme, I really could not conceive anything non-humanoid.
OK, humanoid is one thing. But, all those muscles look exceptionally human, right? Is that really necessary? Not really. My primary desire was to give it big fists. This is a pretty common theme, in order to connote "fighting". But my first sketches had several problems.
It's funny TaB mentioned Popeye, because many of my early sketches had a much less muscular torso and upper arms. So the torso and arms were kind of skinny with big powerful forearms and fists. Unfortunately, the big forearms made all the sketches look like Popeye. I never thought about the brow resembling Popeye, but now that TaB mentioned it, I see the resemblance.
When I went the other direction and tried to give it a rounded non-muscular torso and arms, it ended up looking like a Dusknoir ripoff. Particularly, with the whole "no legs" thing.
I couldn't get something I liked sufficiently, without trashing the base concept. So, I added a bunch of musculature to the form. Even though this is human-looking, I have a couple of reasons I believe it can still work:
1) Machamp has clearly human bodybuilder musculature, so it's not unprecedented.
2) Machamp has four arms and a frog-face to make it "non-human". This has no legs, huge forearms, and no face to make it non-human.
3) IMO, the biggest problem with human-looking pokemon, is that it is hard to believe they will follow a human trainer. But, by making this a faceless fighting drone, it's easy to imagine it doing battle for a trainer. By giving it a Djinni-like backstory and visual look, it makes it even easier to imagine it as a creature that will do a human's bidding. What's more common with genies, than the concept of a human "master", right?
4) This is the design artwork. The end result will be a game sprite. The sprite will surely look more pokemon-ish than the design artwork. Look at the Syclant art and sprite to see what I mean.
A bit on my color choices -- I like the off-white skin color, because it seems "ghosty", but other colors could work well. I used the red for his tats, because red feels like "fighting" to me. Maybe I'm just so used to the red label background on the ingame "Fight" icon for move and pokemon type. The gold is clearly for a ceremonial feel. It adds impact to the pokemon. I'm open to suggestions on colors.
Here's some more background on the tattoos. In some earlier designs, I was thinking of a training-obsessed pokemon that was really dark and macabre. I imagined it having a bunch of self-inflicted scars from punishing itself for battle losses. Pretty twisted, right? Some of the drawings were fairly cool-looking. Ultimately, I decided self-mutilation was just too grisly for pokemon and I scrapped the idea. But, I kept looking at the drawings of this creature with scars all over its back. I realized the scars could be converted into a cool cross-hatched tribal tattoo pattern. That's what made it to the final product. IMO, the tats on this guy are the real differentiator. They were a pain in the ass to get right, but I think they are worth it. Now you know how they came about. Weird, huh?
I have some loose concepts about the golden bands being magical and in some way related to the Fighting Spirit's ability to cross into this world. I'd also like the number of bands to mean something. Age? Training level, like martial arts belts? I'd love some creative suggestions.
I'll end this with a tidbit about the featureless face. As I already mentioned, I wanted to manipulate the face to take away its human-ness. That got me thinking: When fighting, aren't facial features a big liability? Black eyes, broken noses, busted lips... Wouldn't it be better if fighters had no face at all? Of course then they would have no senses, so that would suck. But, a Sixth Sense would take care of that. So, I erased all the facial features and loved the look. I've even taken the concept a little further. I imagine that young Fighting Spirits are actually born with full faces. But, as they train and gain fighting prowess, they rely more and more on their sixth sense and the normal sense organs fade away. Eventually, when fully evolved, they have no face at all and rely exclusively on their sixth sense.
There's everything I can think of at the moment. I hope this has helped some of you understand more about my design. If anyone has additional interpretation, I'm interested to hear it.