You're the one who's insulting me. You're the one who is assuming things about black blade or how Adv.CoC functions. You're the one who thinks Black Blade and Adv.Coc can't go along well despite knowing nothing about them.
And the fact you get frustrated, don't even read and start insulting me in a discussion alone shows the baseless argument you present.
Haki was, is, and will always be a boost to your combat. Roger, Shanks, etc using it on blades weapon aren't retarded. Luffy using it will still remain a gomu gomu brawler; he won't become a coc-man or something. If Sanji had it, he'd still be a kicker. And for the last time, Oda is not retarded for giving CoC to the one aspiring to be WSS as his next ceiling.
It's absolutely ridiculous to try and say CoC coating isn't a boost for swordsmen eventhough in terms of usage so far it's been very very similar to Ryou. It could just boost your AP insanely.