the aura has no effect on how zoro cuts someone just zoro using more haki
as u can see enma and all swords are coated in haki
as u can see enma and all swords are coated in haki
Zoros first attack on Kaido, Oni Giri, didnt manage to cut him. After that Zoro said that he needs to unleash Enma more.
After that Dragon Blaze( with aura ) was implied to hurt Kaido if he didnt dodge. Tatsumaki( with aura ) managed to cut Kaido.