Fan Casting Took a Level in Kindness in Sort by Tropes

A sweet trope in which a Jerkass develops a nicer attitude over time and becomes a genuinely pleasant person (or, at worst, a Jerk with a Heart of Gold). Usually this can be due to Character Development. A Heel–Face Turn may be involved as well. In some cases this may be a case of Characterization Marches On; as the series progresses, the writers realized that a nicer character fit the changing tone better than the original idea. This trope also covers situations where a character with a Hidden Heart of Gold feels safe enough to show his gentler side (in the presence of the main characters, anyway).