I really agree with the others here.
I was with a partner for years who was very physically attractive, and very hot/cold. When things were good they were perfect. But never for long.
The allure of the highs is magnetic.
But the person you are describing is CONDITIONED to exist in instability and drama. In the absence of it, he very well may feel an unconscious need to create it. Things and patterns that are familiar are comfortable. That’s how we’re wired.
It could take a long time to see and change that programming in therapy.
RDMercer