look at yamato, he has adcoc but its not yonko level adcoc, shanks had probably adcoc but not that strong and mihawk matched him at that time with his sworskill power and his coa
but shanks took the escalator to a another level to become a yonko monster matching wb and kaido bt mihawk stayyed at his commander/admiral level
but shanks took the escalator to a another level to become a yonko monster matching wb and kaido bt mihawk stayyed at his commander/admiral level
Do you see how ridiculous this is?
Not even PK level Roger "who loved his sword so much he named his son after it" was able to forge a black blade.
Yonko level Oden failed too.
Only "Sword God" Ryuma was able to do it other than Mihawk. Later in the series, Joyboy was compared to Ryuma. It's a subtle hint that Ryuma is on Joyboy's level.