sentences:  When swung over, , the bat changes into a katana.After training under his father, Yamamoto receives , a shinai that changes into a katana while using the .His training in the series' alternate future allows him to create an affinity between the Shigure Kintoki and his Rain Flame, something his adult self could not accomplish, due to the irregular nature of the blade, a high concentration of Rain flames from the Vongola Ring were needed to create that affinity.