Either Zoro used ACoC before Luffy with Asura (which shows that even tho Luffy is the CoC master, Zoro unlocked the only meaningful ability so far faster) or Zoro didn't use ACoC whatsoever with Asura and thus, his CoA was enough to scar the WSC in his Strongest form (imagine what ACoC Asura would do LOL). I'm personally fine with both so them Zoro haters have to pick their poison. Funny how they started saying that it wasn't CoC and only CoA just to quickly change their sides when they realized that they indirectly wanked Zoro LMFAO.