As with most things CoA related, it’s not been well developed or explained.
I
think what the problem is that our first explanation came from Hyo. And Hyo, being from Wano, doesn’t actually know what Haki is, he calls both CoA and CoC Ryou.
So here
He’s actually describing both CoA
and CoC. He says “All I can teach you… is that which covers the outside.”
So Hyo, despite being a mighty blade in the past, and knowing how to use Ryou, can’t teach the second step, because it’s actually CoC, not CoA. Hyo doesn’t have CoC, he can’t use it. But because he’s from Wano, and doesn’t actually know what CoC is, or Haki, it’s just called Ryou.
But we can see that Luffy can do the second step, but only
unconsciously, because it’s CoC, which Luffy has and can use.
Then it’s not until here that Luffy actually pieces together what Hyo was trying to teach him
And that the second step is actually CoC, not CoA as he’s been assuming.
That’s the only thing that makes sense to me anyway.
So how it goes is
Step Zero- bog standard CoA
Step One- CoA Ryou. The thing that Hyogoro
can teach, Armament Haki that has the sort of forcefield look. Also used by Sentomaru
Step Two- CoC Ryou. Hyogoro couldn’t teach it, because it was CoC, Luffy was using it accidentally, not really knowing what he was doing until the fight on the roof. Zoro also seems to have used it, again accidentally, when he scarred Kaido.
[automerge]1626600301[/automerge]
That’s what I think, anyway, it’s still pretty messy