One Piece is a series that places a heavy emphasis on its established characters. While many series will seek to strengthen their leads, One Piece goes a few steps further, with an added focus on supporting characters and antagonists returning. One of the biggest examples of this was the time spent between the time skip, a period of 2 years, in which each Straw Hat trained to strengthen themselves for the New World. This is just one of a few moments in which a character returns far stronger than before. This list will look at some characters who deserve to be strengthened further before the series.