Dragon Ball Super: Why Android 17 Is So Powerful | Screen Rant

Android 17 suddenly became one of the strongest heroes in the world of Dragon Ball when he was brought back for Dragon Ball Super's Tournament of Power. Originally, Android 17 and his sister, Android 18, were incredibly powerful villains who fought the Z-Warriors in the Cell Saga. Android 17 was matched up with Piccolo (who he was unable to beat) and absorbed by Cell. After Cell was defeated and 17 was saved, he disappeared from the anime. He was later used as a villain in Dragon Ball GT, which is no longer canon.