Well, it's good that you are recognizing it's a problem and you are inquiring about it.

There is nothing wrong with having strong views/opinions about things, most successful/striving individuals do and have what is called "Narcissistic Traits". However, it can become a problem when an individual has to have everyone else "see it their way" to a point where if another person doesn't, they will begin to tear the other individual down, and with "pleasure". Then their Narcissism becomes obcessive and manipulative and that usually stems from low self esteem where the individual practices unhealthy behavior patterns in and effort to build up their low self esteem. However, they don't actually realize this about themselves and need to think of themselves as "the best or greatest".

What you have discribed about your trolling is that you seem to need to state what your opinion is and lay in wait for anyone to challenge you to where you engage until you feel you have somehow "won" the battle. Or, maybe you go trolling until you find some kind of oponent already stating their view that is different from yours and see that as an invitation too.

You have stated that you have NPD, well, it's important that you learn how you developed that and see if you can get to the bottom of "why" you need to challenge and insist on being the top of the heap if you can. It can come from a history where you did not have what you needed and ended up developing this to "self protect" somehow. A lot of times there is a lot of hidden anger involved so it would be nice if you could work that out and release it in healthier ways. It's such a waste of time to spend so much time trolling and manipulating to find your sense of "control". It's ok to have your strong opinions, and even defend them from time to time, but trolling and looking to do that is really not productive.