Ryokugyu's Possible Abilities [CHAPTER 905]

Ryokugyu or Green Bull is an admiral of the Marine HQ, and there's little that is known about him. What we know, though, is that he is on par with Kizaru and Fujitora, which is quite an amazing feat.

The manga has finally shown us small amounts of his traits and personality on Chapter 905. Here we can see Fujitora and plot-covered Ryokugyu talking with each other.

Ryokugyu is shown as a laid back person and a person who knows about his stuff with the marines. In the last panel, he is shown to have not eaten anything... for the past 3 YEARS! That's amazing. From this information, we can have theories about his strengths and abilities.

Theory #1: He is part machine.
Ryokugyu is shown to talk casually about Vegapunk, so there might be a possibility that Vegapunk might have modified Ryokugyu's body to the point where he doesn't need to eat anymore.

Theory #2: He is from an unknown race.
One Piece seems to have a lot of diversity when it comes to species, especially in Big Mom's territories. There might be a race, somewhere, that can eat but don't need to do it.

Theory #3: He is affected by a devil fruit.
We already know that there's a devil fruit that can exchange its owner's life for the immortality of another person. There's a chance that Ryokugyu is affected by that kind of devil fruit, not necessarily the Ope-Ope fruit.

Theory #4: He has a devil fruit that lets him not eat anymore.
So this is the theory that I'm confident of because it makes a lot of sense. What I believe is there is a devil fruit that doesn't require him to eat anything anymore. The one that makes the most sense for me is. wait for it, plants. His admiral nickname is the Green Bull, and what other things are green? Plants. The "Bull" part isn't necessarily about aggressive abilities since it's more about the admiral's personality, not their strengths.

But why does a plant-related  Devil Fruit let him not eat anymore? This is where your grade school knowledge comes to the rescue. Plants don't eat, they use photosynthesis for their survival. And here's the amazing part: what are the stuff plants need for photosynthesis?

Water and sunlight. And who're the guys who have very related powers?

Exactly.