Ashura itself isn't CoC, it's a sword technique, Zoro unlocked CoC now which means that now all of his attacks including Tatsumaki, Onigiri etc.... will have CoC in them even the regular sword swings. Zoro has entered top teir territory and next time he uses Ashura the attack power will be much more than what he did while being half dead. I think that End of Wano Zoro will be very close to EoW Luffy with Luffy being the overall stronger of the 2