Precia in Game Theory. At the very least, she makes an effort to act pleasant instead of abusing Fate, so she's already miles ahead of her canon counterpart, and she does seem to get somewhat genuinely nicer as the story progresses.
In Address Unknown, Rainbow Dash grudgingly agrees to take care of a temporarily blinded Derpy, who has recently started a relationship with Twilight. While trying to get to sleep on Derpy's couch, she is forced to confront her responsibility for contributing to Derpy's lifelong misery, and makes a tearful apology the following morning. Derpy forgives her and the two agree to start over.
In the Total Drama story, Legacy, both Heather and Duncan have grown up, figuratively as well as literally, in the ten years since they were on the show. Duncan has even learned basic precepts of chivalry.
The film Son Of Godzilla is the start of showing the King Of The Monster's more loving fatherly side. Especially towards the end where he embraces his new son to keep him from freezing to death.
The whole point of the Film Thor, which is an inversion of Captain America: The First Avenger. Whereas Captain Rogers was granted power because of his kindness and decency, Thor had to learn kindness and decency first to be worthy of his power.
Thor: The Dark World: Downplayed with Loki. He is still evil, but he risks his life to save Jane Foster. Moreover, Loki-as-Odin could've temporarily imprisoned Thor for his treason and made him feel guilty for disobeying his king's order. Thor being on Earth still suits Loki's self-serving agenda, but it's a small step forward that Loki chose to be kind to his brother (i.e. letting him be happy with Jane and making him feel like he did his father proud) when he could've been cruel. If you contrast this scene with the one in Thor where Loki talks to his brother while the latter is a prisoner of SHIELD, Loki's manipulation of his sibling in the sequel is much gentler.
Karkat in Homestuck becomes less of a Troll and more interested in the success of his prior antagonists. And if he's not a Jerk with a Heart of Gold, at least he's a shrewd enough leader to know when to play Team Mom for the other trolls.
John, too. As he becomes more of an All-Loving Hero — especially when contrasted with the other kids' Character Development, which often took them in darker directions — it can be hard to remember that this is the same guy that who, in his first pesterlog, responded to Dave's gleeful discovery of a bottle of apple juice by joking that it might actually be full of pee.
EB: all im saying is don't you think monster howie mandel has the power to do something as simple as reseal a bottle?