His final moment is cutting down Kaido over the Flower Capital, like Ryuma did. The Oden parallel is done with the scar, the Ryuma one needs to be finished as well. That’s the final test for if ZKK happens or not.
Will he beat King? I don’t know. He’s pretty badly fucked up. In his favour is that King will be the second last Beast Pirate to fall, so there’s a lot of time for Zoro to recover. Against that- Zoro is really injured, Marco isn’t, and how much is Oda really going to wank Zoro anyway? Throwing in beating a YC1 while half dead even after all his rooftop feats? I’d certainly celebrate, but jesus.