User blog comment:Kaido King of the Beasts/Chapter 862: Semi-Charmed Kind of Life/@comment-28966845-20170413122438/@comment-28966845-20170413172150

Zoro only used koka in dressrosa arc and i refuse to believe that for 2 years he was only learning hardening.

So yeah he propably has some tricks in his sleeve that keeps for strong enemies (and not pawny picas)