The next panel he had cuts. It vanished after he transformed into a dragon so it is not even comparable.
Yet he didn´t have any cut now, either when he take all cuts in dragon form, all vanished.
Kaido literally proof it here that only ryu user can hurt him:
Later in same chapter we know that all use Ryu step one, Hyo himself proof that wano samurai could have ryu.
Their is no way that base Zoro without HAKI or Killer could cut a Kaido, their is not a single point to believe it since Kaido himself make the point that blades usually not cut him.
Yes you can't hurt Kaido without Ryou and Killer doesn't have Ryou which is why he was glad Luffy did. He didn't cut Kaido either. There's a zoomed in panel and Kaido has no cuts
They only manage to little hurt him, Kaido heal power is too great to give him a major wound, he literally pointed it against the Scabbards:
And Killer indeed cut Kaido, you can see around his head little blood similar as what Zoro did:
Around Kaido head: Bloood which he take from Killer
Around Kaido belly: Blood which he take from Zoro
You can only wound Kaido via ryu, another else wouldn´t work, blades neither.
Luffy hurt and bring Kaido in blood with a g3 attack, yet Kong gun didn´t even hurt him much as before, Kaido was prepared this time.
No black swords and neither the black lightning.
You mean like this?
Neither of these guys had black sword yet their where able to cut Kaido and you only can cut him via Ryu.
They didn't. There's no indication there that they used haki. There's confirmation that neither Kid nor Killer have Ryou
Because Luffy use penetration haki a step above Ryu with even Hyo proof in udon back then.
Ofc Killer or Kid haven´t it, Kaido literally show guys like Roger,Oden and co having it and only match to hit him like that, with make Luffy rare, he don´t mentioned the retainers.