Two options right now
1-Zoro falls into momo's back
2-He falls into onigashima ground(I don't think he will fall into ringo) The thing is who will help him if Sanji is out too?Hiyori is on the back part of onigashima right?and Denjiro is also there zoro is in the right part
So if they are in the back part they'll have to turn around will they find him?
I also wouldn't care if zoro last role is a plot with Orochi/hiyori I also don't think zkk will happen
But the question is when black blade?not this arc imo since zoro has to mastered Enma wich means EoW is staying with the sword