Well, Negan first appears in the series as a major antagonist. He has a very distinct personality. He's confident, often to the point of being cocky. His group, the Saviors, would extort other communities for resources. He uses fear as a tool to control those around him. His actions have a huge impact on the other characters in the show, like Rick and his group.
Rick is a very likely character to interact with Negan in hurt Negan fanfiction. Their relationship has been a central part of the original story, and in fanfiction, their interactions could be further explored, especially if Negan is in a 'hurt' state. Another character could be Carl. Carl had his own complex relationship with Negan, and in fanfiction, their dynamic could be developed in new ways.
At first, Winchester was pampered, but her nature was not bad. She was the illegitimate daughter of the Wen Family and was sent to the Wen Family to take over the identity of the Wen Family's daughter. She was a willful young lady, but in the end, she got along well with Wen Heng and liked Wen Siguan. According to this information, it could be said that Winchester was not a bad person.
Well, it depends on your perspective. But generally, Negan is considered bad in the comic because of his cruel and violent actions towards the main characters.