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Have an example (or several)? As-is, what you're describing here sounds like either a (horror-related) Central Theme being represented by a Motif, or the fear being the Central Theme itself.
The best example I can think of is from I Have No Mouth, and I Must Scream.
In that story Ellen has a phobia of the color yellow, AM knows this so designed tortures with a recurring theme of yellow.
Sounds like Kryptonite Is Everywhere, except replace "weakness" with "phobia"
We can never truly eradicate the coronavirus, but we can suppress its threat like influenza
We do have Played for Horror.
Current Project: Incorruptible Pure Pureness
I might've asked this before and it got buried minths ago but, is it a trope for when a recurring theme is played for horror?