Originally Posted by UzumakiUchiha
What is Yonkou?
how does luffy hands change to metal when he punches, like he did when they were headed to fish island?
Yonkou are the Four Emperors of the Pirates: Shanks, Blackbeard, Kaidou and Big Mom. And Luffy's hands don't turn into metal, simply his Busoshoku/Color of Arms Haki hardens them.
And welcome to this side of the forum, never saw you around before.