Actually, it makes a lot of sense. It never made sense that CP9 didn't have Haki to begin with. And when people start with all the crap that Rokushiki is muscles, none of this is stated in the manga. Go check, some is muscles, some is not. Lucci said: "Our power is classified, we'll never tell you how we do it."
Everyone arguing that they know how Rokushiki works is wrong because the manga tells you, "Nope, not telling you."
Everyone telling you "Tekkai is muscles" is wrong. They're using the real life inspiration for Tekkai, and then using it to extrapolate a technique.
We are only told:
No one says muscles. He never says how it has tempered his body. just that it has. Kamie is literally never explained.
Luffy also never gets hit full on by Tekkai attacks. He dodges everyone. Oda could say: "Instinct told Luffy to dodge it, despite being rubber."
And they
even see them saying you can't beat the Six Powrs with strength. If the Six Powers are "physical strength", that makes no sense. Look at Kamie, that's classic CoO.
A lot of people argued that it made no sense for CP9 to not have Haki, and came up with al sorts of fanon as to why. But don't forget, fanon is not canon.
Rokushiki is physical strength, is never stated, Here are two things that are undeniably stated: "You can't beat Rokushiki with physical strength", already drawing a distinction. Rokushiki's true nature is classified, that's another one.
Here's the Vivre Card: Mantra and Rokushiki are essentially Haki.
Here's Who's Who showing: Rokushki = Haki.
Best guess is CoO and CoA = Kamie and Tekkai. CoA= Rokougan, and you can try and use your muscles to stimulate them, but it won't work.
The only person who did got murked by Lucci for being a clown.