Sword synergy might be a factor in swordsmanship.
With what we see in the manga enma has brought out the best in Zoro in a way maybe no other sword can and he will inevitably turn it into a black blade which oden couldn't do. Maybe Oden lacked something enma needed beyond haki which we know Oden could give out in spades. I dont know how to put it into words but the atmosphere Zoro gives off seems to match what a sword of that nature and caliber gives. I think this can best be seen when Zoro takes inspiration for his new sword style from enma while Oden named his sword style after himself.
Oden was a man born to be a king acknowledge it and refused the accept that part of himself until it was too late.
Zoro was also born to be a king but never realised and gave off the impression subconsciously. When he was presented with the reality he was a king he embraced it.
With what we see in the manga enma has brought out the best in Zoro in a way maybe no other sword can and he will inevitably turn it into a black blade which oden couldn't do. Maybe Oden lacked something enma needed beyond haki which we know Oden could give out in spades. I dont know how to put it into words but the atmosphere Zoro gives off seems to match what a sword of that nature and caliber gives. I think this can best be seen when Zoro takes inspiration for his new sword style from enma while Oden named his sword style after himself.
Oden was a man born to be a king acknowledge it and refused the accept that part of himself until it was too late.
Zoro was also born to be a king but never realised and gave off the impression subconsciously. When he was presented with the reality he was a king he embraced it.