I'm not surprise Luffy wants take on the 4 emperors, we all know Luffy by now

. What surprise me is that the fact Luffy wants to whip the floor with Shanks that was interesting, because Luffy does want to meet Shanks again after becoming a strong pirate and return the straw hat back to him. We don't know all Luffy feats for the time-skip since Luffy hasn't really gotten into a serious fight yet, we'll see when Luffy goes up against Kaido. I think Luffy will get a power up again like he did during cp9 arc, he going to need it against Shanks and Black Beard.