Theory I think a human fire created the mother flame.

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This post got zero hits on reddit but I'm hoping here will be a little different.

During the void century and right before, we can infer the prosperity the ancient kingdom worked for began to be challenged. I think before this peace was maintained or at least worked towards. So I think it's possible the death of an original sun god Nika is what let other countries start standing together. Similar to how whitebeards death triggering a new era. If this figure was beloved, people could possibly have created the Nika fruit through thier desire for his return.



In the sense that chopper is a Human reindeer because of his devil fruit, I think Nika could have been a human flame.

With this idea all we would need to do is look at Ceasars smile to have a basic idea of how it would work and what he would be capable of. The axolotl fruit being "fed" to a massive poison gas gave it a free forming body. It was capable of a much more fluid hybrid state as well as the ability to split itself into pieces that all contained sentience.

If a human fire could split himself into pieces, all the little flame parts of himself would remain sentient and alive
This gives the possibility of a limitless energy that could be shared. Presumably as long as he lived. The axolotl turning his mouth into a cannon is almost as much free creation as luffy has(turning hair into googles).
 
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