@zzShinichi @JoNdule
Not based on Koby's fist, but the punch after.. It seems like AdCoC '' no touch ''..
So yeah, Koby's used AdCoC there.. And the training is Haki relevant, since it was refered once more in this chapter..
Also Zoro never used AdCoC and never will, that's why Black Blades exist..
It seems it's as well Koby's first time unlocking AdCoC, i would say..
Now when did he unlock CoC then..