You could either be referring to a flat character (characters in a story who do not go through substantial change or growth throughout the story) or a static character (a character who goes through no change)
static, he doesnt change
The word is static. It means unvarying, consistent, and lacking in change.
Static secondary character
Anatomically, a disease is internal. However, when an author includes a disease to be a conflict among a character or characters, it all depends how the author illustrates the response of the character to the disease. Usually if the disease creates isolation or insanity, you can say that the disease is external cause the character might lose focus on reality and society.
it doesnt change
it doesnt change you dumb
it doesnt.
A character who does not undergo any change throughout a story is considered a static or a flat character, in contrast to a dynamic character or a round character, who undergoes a change throughout the story.
reader; character
susanna english because she doesnt change throughout the story
You shouldn't have to change freon, it doesnt go bad.
Independent Variable