Vegeta

Vegeta lands on Earth as the villain of the arc, kills his own partner for being disappointing, and leaves alive because Goku lets him. That decision shapes the next thirty years. He comes back as a rival, then a reluctant ally, then a resident, and he spends the entire time roughly one step behind a man he considers his inferior by birth. Being second is the wound the character is built around.

The softening is slow and never complete. He marries Bulma, raises two children, trains in a gravity chamber inside his father-in-law's company building, and would rather die than say any of it out loud. His best moments come when pride finally costs him something: the fights he loses on purpose, the ones he throws away, and the single occasion where he admits, quietly, who the better fighter is.

He is named after the word vegetable, as are his father and the planet they ruled, which is either the least dignified thing about him or the most. Fans have argued for decades that his arc is the strongest writing in Dragon Ball, and the argument is not hard to make.