Remember Luffy’s red rock that hitted kaido and how that technique made a impact on us viewers specially how that impacted kaido and this is the time when luffy didnt mastered his kings haki but made kaido threw up blood.
Imagine now what if this red hawk, red rock of luffy would covered by kings haki? Just how much fire it would produce? Or how much it would hurt kaido?
Imagine now what if this red hawk, red rock of luffy would covered by kings haki? Just how much fire it would produce? Or how much it would hurt kaido?