I didn't say you claimed it was a final diagnosis. I'm saying your argument repeatedly relies on NPD as though it were established enough to make categorical predictions about how this person will behave. Saying "we're talking about NPD here" and "a narcissist will always..." is treating it as an established premise regardless of the disclaimer.
And saying you "know how to handle Cluster B" doesn't establish that your interpretation is correct either. That's the point I'm challenging. Your personal experience can tell you what you've encountered, but it doesn't turn those experiences into general rules about how people with Cluster B traits behave.
The "you're lost and I'm the one who understands" framing also doesn't address the argument. If something I said is wrong, you can point to the specific inference that fails. Telling me I'm spiraling because I don't accept your interpretation just replaces an argument with an assertion of authority.