The "spikes" could just be...well...spikes. Dragons are known to have spines and spikes along their body, in various depictions.
Or they could even be feathers. Like the more up-to-date versions of dinosaurs. Or a reference to other feathered serpent dragons from mythology
https://tvtropes.org/pmwiki/pmwiki.php/Main/FeatheredDragons
https://www.thearchaeologist.org/bl...atl-the-feathered-serpent-god#google_vignette
But...part of me just can't help but wonder...
(Source Dragon of Motion)
(Morro Dragon)
Maybe this is just me refusing to let go of a old theory I had. But, I just can't help thinking that Loki could be made of Legos.
We never did find out where those Legos that Road had came from. Elbaph doesn't seem to have any factories or any way to manufacture plastic on their own.
If Loki's Fruit is actually one of the God Fruits, it's probably got some weird power tied to it, that you wouldn't expect. Like the Luffy's Fruit being all about "Imagination". Or Imu's Fruit being all about "Board Games". If Loki's Fruit is one of the God Fruits, it'd make some sense if Loki had power over "Toys". It'd maintain the theme of the God Fruits being based around "Literally Playing God".
That would potentially explain where the Legos came from. They could have fallen off of Loki's body, while he was fighting all the Giants and getting chained up in the Underworld Layer of Elbaph.
If Loki's dragon form is made of Legos, that may also explain what the "spiky things" on Loki's back are. They're different kind of Legos for the details. "Spikes" to make the design look cooler.
So, maybe next chapter or so...we could see Loki get attacked and get a hole blown through his chest. Everyone thinks he's a goner. But, then we zoom in and we see all these square blocks reforming around him and repairing the hole. Then we get the Devil Fruit name drop. Personally, I'm still betting on the Earth God Fruit for Loki, but we'll see.
Now, I'll admit, this wouldn't really explain the storm-powers. Unless they're..."electronic features" built into the Lego build? But, the storm powers do hint that this really is a "Western Fire" dragon, rather than a imitation built from Lego. But, again, we'll see.
But...if you want a alternate theory for why Loki's Dragon form looks all black, there could be another explanation.
Luffy's Nika Form is White. And, as far as we can tell, Imu's mainly Black colored, in most of their forms.
I feel like that implies there's "White" and "Black" sides to this game the Gods are playing with each other. 2 "White" Gods. and 2 "Black" Gods. Each taking different sides. Like in Chess or Go.
So, if we assume all 3 of these characters have God Fruits. That means:
Luffy is a "Heroic" White God.
Imu is a "Villainous" Black God.
Loki is a "Heroic" Black God.
Which should mean, the final God should be a "Villainous" White God. Probably something to do with Davy Jones? But, we'll see about that.
We don't know if any of that is true. Oda might be going for something else entirely. But, we'll see.
Also, here's a few types of storm dragons that Loki could be taking some influence from, from various mythologies, just for fun.
https://en.wikipedia.org/wiki/Zduhać
https://en.wikipedia.org/wiki/Quetzalcoatl
https://tvtropes.org/pmwiki/pmwiki.php/Main/FeatheredDragons
Also, one other thing to point out. Do you notice what Loki's Dragon form DOESN'T have? Think about it for a second.
....Time's up!
Loki doesn't have a "Awakening Ribbon" around him! Which means...Loki still needs to awaken this Fruit! So, whatever the Legendary Devil Fruit actually is...we haven't technically seen it's final form, yet!
So, we'll see. We still haven't gotten the name of this Legendary Devil Fruit, yet. So, I think Oda is waiting to reveal SOMETHING about this Fruit. But, chances are, what we're seeing is what Loki's Dragon form looks like. I don't think it's still supposed to be a silhouette. With Imu, it's a little less clear, working a lot with shadows and possessions. But, Loki actually has a lot of details on him, already. So, I think this is the design. But, we could get a twist with it.