Luffy is the upcoming 5th power.
I believe Luffy will be considered a "true" yonkou at the end of the arc (kaidous forces might be immensly diminished/reduced after this arc, thus no longer being enough to have the overall influence/power of a true yonkou, but as an individual still having the strength to face any emperor in a 1v1). Luffy himself should once more (just like vs Kata) receive an huge upgrade powerwise (awakeing (whatever that will be worth?) g5, better CoA, CoC etc) so should the crewmembers (jinbei should not be forgotten). Furthermore there is a powerboost through new allies (samurai, ninja, possibly 1 SN, who would then remain permanent ally)).
There is still to consider the option of the SHGrandfleet members get battle prowess/powerupgrades too.
He's not a mere rookies anymore that you should expect him to have difficulty with a fucking Headliners.
While i agree that he should not have real difficulties with the headliners, the amount of how easily they r defeated still makes them look like ... well real bad. I might at least make him withstand more than a few secs, or rather say 2 attacks.... of course there is still the possibility of some headliners which are far more powerful than Holdem and Sheepshead as the ones we know. I mean Hawkins and Drake should definately be far stronger than what sheepshead seems to be.
BTW what is/means: "Atamayama"? http://mangaseeonlin...917-page-8.html
Kiku seems to know about Shoutenmaru, interesting, since the first time when i heard about a food thief i thought it clearly is law who teleports there snatches the food and then teleports away again, but does not seem to be the case...