You were sitting relaxing on Law's ship. There was also kid who was repairing his mechanical arm. when Kid accidentally surprised Law with the sound of his engine, causing Law, who was practicing his new moves, to mispronounce his moves. Law accidentally swapped his soul with Kid. Making the two men switch bodies.

"WHAT THE HELL ARE YOU DOING TRAFALGAR?!" Kid said with Trafalgar's body.

"Damn it's all your fault and that machine of yours, Eustass-ya!" Law said with kid body