After reading the last few chapters (930-932) and seeing Orochi’s abilities/devil fruit powers briefly shown, it’s possible that Orochi’s devil fruit takes inspiration from the Greek mythological creature the Hydra, as they are very similar, so for this theory, I’ll be speaking about the Hydra’s mythology, which could’ve offered Oda further inspiration.
Now in Greek mythology, the Lernaean Hydra was a creature with numerous heads that when chopped off, grew back with double the amount as before. It was also said to have poisonous breath and blood (And we all know how much Oda likes to poison people in the story).
The Hydra was defeated by Heracles, and the only way he could defeat it was by chopping a head off and then immediately holding a burning club to the wound to almost cauterise it.
This opens up so many plot lines, and I’ll talk about a few of the options for where the story could go if Oda has taken inspiration from the Hydra mythology:
Kinemon is somehow capable of generating, attacking with and cutting fire with one of his swords; this would be a perfect way to kill a hydra-like creature. It would be nice to see Kinemon symbolically take back the country from Orochi and get his time to shine as well, he would just need to cut it and then set it alight and the heads would not grow back just like Heracles did.
2. Team-up of the Samurai
As we know Kinemon can cut fire. There could be other elemental sword cutters in Wano, in the form of other samurai, and they could play a part and each cut off a head with their element.
3. Sanji and Zoro
It’s been a long while since the last time Sanji and Zoro teamed up.
I can see this happening as Zoro goes along cutting the heads, Sanji comes in and adds fire with a kick which would cauterise it just like in the Myths. Perhaps Zoro tries to take Orochi on on his own and thinks he’s done it after cutting all the heads off at once but then they all grow back. That would be a great plot point for me, and require Zoro to forgive Sanji and let him help him.
*Theory by Th3oryw0rld