- The Ope Ope no Mi enables Law to cut people into pieces and shamble them together as he pleases.
- Prior to the time skip the pieces could act separated from each other but the re-puzzled person could not control pieces that were not their own. (Or so it seemed from the scene we saw him in action.)
Looking at it that way it should actually not be possible for the human part of the centaur to control the animal part.
I have several theories on that:
- Practice Makes Perfect: He trained during the time-skip. Simple as that.
- Piece of Me: We saw that Law can cut a heart from a body and put it into a different one. So maybe he cut the hearts of the humans and put them into the body of the animals. Since the heart is still alive so are they but by putting it into the animal body they can control that body. The flaw in that theory is that I am not sure how the human part of the body is affected by this.
- Thriller Bark Inverted: Remember when Hawkins said he sees the shadow of death on Brownbeard? Assuming Hawkins was correct and Brownbeard did die, how can he be alive? I kinda doubt Law came to his rescue. Now what I found strange is the way he was introduced in that info box. Not as "Brownbeard" but as "Boss". This is probably done in order to not reveal the name just yet. Why would that be necessary? We know the guy already. Unless he is a completely different person in a patched-together body just like the zombies on Thriller Bark. It might also explain the corpses inside the ice.
That concludes my current thoughts on the centaurs. Man, does my head hurt!
Minor side note: Did anyone notice that one centaur on page 2 in the bottom panel? No, not the girl! The other guy. He is one of the members of Brownbeards crew 2 years ago (compare chapter 594).