During Luffy's two years of training, Kid challenged one of the Four Emperors, Shanks, but lost one of his arms in the process. He attempted to form an alliance with the On Air Pirates and Hawkins Pirates to challenge the Red Hair Pirates once more, but the alliance fell apart after an attack from another Emperor, Kaidou, which led to his imprisonment at Wano Country, where he would eventually reunite with Luffy. Though nominally acting in self-interest towards vengeance and glory, Kid's assistance towards the Ninja-Pirate-Mink-Samurai Alliance was instrumental in defeating Kaidou, Big Mom, and the Beasts Pirates.