I'll start with a clear example. You are writing an essay about the film The Wizard of Oz. Following the rules of titles, you put the film title in italics whenever you use it.
But then you use the words in the context of explaining the story, such as, "They tell her to seek help from the Wizard of Oz."
This is not a reference to the title. In the context of sharing the plot or quoting dialog, there is no reason to put the phrase "Wizard of Oz" in italics.
So, why is my instinct telling me to do so? Not asking you to evaluate my mental state, just saying that I know this is kind of a 'dumb question'. I can't see any standardized formatting reason why you should put the phrase in the title in italics, when it's not referencing the title directly. And yet, I feel like there is an applicable rule I'm forgetting, that is making me lean toward the italics button.
Regarding medium - this is for a weekly free-writing "journal" assignment in a college English class, which the instructor, syllabus and instructions specifically say does not have to meet any formal rules on formatting, punctuation, grammar, citations etc. But it really got me to wondering, because I'm that pedantic, how I should be handling that situation in formal writing situation? And a search of SE and the wider internet yielded no obvious answers.
And while I tried to use a fairly universal example for clarity, the actual subject of the paper I'm writing is The Good Place. Which does add the wrinkle of; if I always put Good Place in italics, should I also put Bad Place in italics? And people thought the philosophy in this show was stomach-ache-inducing. :) Thanks, in advance, for any input.