Ok, so now that I had a little bit of time to think about it, I'd like to put my own concept on the prospect of Luffy's Devil fruit actually being the "Nika Nika no Mi", without the whole "Oil concept" that the person in the video described.
Now in order for this to make the most sense, I highly suggest you guys read my One Piece/FF Connection theory, in regards to Devil Fruits actually being human abilities, prior to becoming Devil Fruits. You can find that here.
https://worstgen.alwaysdata.net/for...abilities-before-becoming-devil-fruits.16856/
Now if you bear this theory above in mind, then it would be completely plausible, that Nika himself, actually possessed the power of Rubber, and was the creator of the "Gomu Gomu no Mi". In that regard, Luffy's devil fruit would not be the "Gomu Gomu no Mi" but rather, the Mythical Zoan fruit the "Nika Nika no Mi". If this was the case, then Luffy's awakening, would actually turn him into the "Fire God Nika". That would mean that Luffy himself wouldn't actually be some chosen one, or reincarnation of a person long dead, but rather, he will have inherited the Will of Nika the Fire god, after consuming the Devil Fruit that he created.
Think about this for a second. Kaido's Devil Fruit, is not actually a "Dragon" devil fruit, but rather a "Fish" Devil Fruit. It's Model just so happens to be the Azure Dragon. But what if, Kaido didn't actually turn into a Dragon when he first consumed the fruit? What if, when he ate it, he was actually, just a fish?
Think about the story that Kaido's Fruit is based off of, about the Koi fish who climbed the Waterfall, and only one fish managed to make it to the top, and in doing so, it turned into a Dragon. What if Kaido's fruit was useless at first, and through constant battles, and struggles, he "Awakened" his Fish devil Fruit, and THAT is when he became the Azure Dragon.
This could be the same principle for Luffy's Devil Fruit. Upon eating the "Gomu Gomu no Mi" he gained some of the abilities of Nika, but it won't be until he awakens, that he is able to harness the true power of the Devil Fruit, which is that of the Sun God. I think this makes so much sense in the Grand Scheme of things, and would tie everything together nicely.
With that being said, what do you guys think?