One Piece. Big Score. Book 10. Furious Demon Viper

Eneru, the rightful god of Skypiea, declares the Upper Yard a battlefield and orders his priests and crew to deal with the unwanted Shandians and outsiders who have arrived from the Blue Sea. God's squad outnumbers their opponents, and the mighty Eneru himself is preparing to join the fight. And according to rumors, his power knows no bounds.
Meanwhile, Luffy and his crew continue their treasure hunt, unaware that they have become embroiled in a decisive battle for the heavenly island...