In Dragon Ball lore, Yamoshi is a legendary Saiyan who first achieved the Super Saiyan state. He fought against evil Saiyans before being defeated. Yamoshi's spirit continued to search for a way to defeat the evil Saiyans after his death. He is credited with devising the Super Saiyan God ritual, which channels power from five Saiyans into a sixth. The legends of Yamoshi's power spread far and wide, even recorded in the history of Namek. Frieza feared the power of the Super Saiyan and ultimately destroyed Planet Vegeta to prevent any Super Saiyans from rising. Goku, Vegeta, and their Saiyan comrades eventually achieved the power of the Super Saiyan. The key to becoming a Super Saiyan is having enough S-Cells, triggered by a strong emotional reaction. Yamoshi's impact on Saiyan lore is significant, leading to the legends of the Super Saiyan and the Super Saiyan God.