uhh ultimately in the end isn't that what it will be he has no weapon for luffy its just gonna be a much bigger punch .
1. God Luffy grabbing the giant sword and “winning like a samurai” Nika was shown with a sword and spear afterall. And he’s using a spear of lightning now.
2. A red rock with the fire from the dreams of all the people in the flower capital.
I wouldn’t just call these big punches