Base Breaking Characters who have killed a major character or another Base Breaking Character within the media that they're in. Because of killing said character, these characters have gained alot of detractors, who are most likely fans of the character that they killed. It also won't help the fact if the character that was killed was a fan favorite character that became popular with the fanbase and the character that killed the former being especially a newcomer at the time. (Examples: Trevor Philips killing Johnny Klebitz, Abby Anderson killing Joel Miller, Kylo Ren killing Han Solo and Gabi Braun killing Sasha Blaus)

NOTE: Characters who are mainly hated for simply killing other known individuals alone can only be considered Base-Breaking Characters if the killings were incorrectly justified by the narrative, or if they were poorly set up or framed in the context of the writing.

Additionally, characters who have killed other characters who are not exactly protagonists or even other Base Breaking Characters but are still major characters or fan favorites could qualify (eg. All of the Blackened from the Danganronpa series)