Wrong… we've barely seen him using his Devil Fruit powers yet. Keep in mind that Leopards have more choices to attack a human with, such as a tail or it's sharp teeth, or claws, therefore I don't think that it will merely be powered up Rokushiki. Look at Blueno for example. And besides, I think some might have mentioned the variations such as tekkai sai and rankyaku sen.
but still.. a fight like that would feel so bland.
Alright, Lucchi lunges and tries to bite Luffy, uses his tail to try and get Luffy, or swipe at Luffy with his claws.
not that eventful, unless some how Lucchi gets a rumble ball and things get more interesting.
I sort of hope that Kaku's DF power makes him the most powerful, then maybe a Kaku vs. Luffy fight.