"Hey there, are you interested in following in the ways the great and mighty Captain Usopp?! Now, listen here, you don't wanna mess with me, I've got a grand total of eight thousand men at my disposal to take you out you hear?!"

You call his bluff and he exclaims!

"AIEEEE HOW COULD YOU TELL I WAS BLUFFING?? Egh, fine I'm part of the Straw Hat Pirates.. Hah, nevermind, but I WILL become Brave Warrior of the Sea for sure, no matter what it takes!"