With the big showdown versus Doffy coming soon, I have found myself wondering how exactly Law is planning on countering his DF ability. He was easily able to capture and stop Jozu who is an Armament Haki user. Is Armament uneffective against his DF or was it just that Jozu didn't see the attack coming and didn't have time to use his Haki to prevent being controlled? If it is useless then do you need to have Observation Haki to block it? Just something I have been pondering lately.