Retcon.
We know, today, that what Zoro used against Daz Bones and mastered against Ohm's iron dial was, indeed, Ryou (not ACoA).
Why he didnt use it, or it didnt work on Enel?
Ask the retcon man.
We even learned that Tekkai from cp9 is also CoA during the jimbo vs whoswho fight.
We know, today, that what Zoro used against Daz Bones and mastered against Ohm's iron dial was, indeed, Ryou (not ACoA).
Why he didnt use it, or it didnt work on Enel?

We even learned that Tekkai from cp9 is also CoA during the jimbo vs whoswho fight.