Son Bra

An original character in a Fan Fiction that doesn't quite meet the conditions of a Mary Sue, but tows the line as a force fed, overpowered, overappreciated, overrated, overexposed character that is forgiven for all actions. These actions include murder and up to genocide, because of terrible writing tropes such as "lost control" or "Mind controlled".

Characters that are like the original character Son Bra in Dragon Ball Multiverse, a fanfiction Dragon Ball Z web comic that has run for over ten years. The character, Son Bra is the daughter of non-canon Vegito and Bulma, and is given extensive potential powers that she cannot control and is very hostile when she gains power. Her father, Vegito vows to kill her if she ever loses herself completely and commits violent crimes, because he would be the only one capable of doing so. Bra then goes on to hurt and kill multiple characters in the series, and even commits a genocide at the tournament in the series. All her actions are forgiven by all the characters for apparently no other reason other than "She couldn't control herself". Not only is she totally forgiven, but another character in the series, Zen Buu; reverses all of her actions without thanks and it's forgotten within seconds by every other character except her father. This makes her father look "evil" in comparison.

Wow, she may not be a Mary Sue level character, but she's certainly at least a Son Bra.