It is entirely possible that both points are true. I don't necessarily think it's healthy, but I've seen BDSM relationships work because one party was flat out abusive - and the other party liked it enough that it didn't matter. In an instance like this, the narcisist/codependant dynamic can function. :shrug:
The narcisist/abusive asshole threshold is what keeps me from being the Dom Violet wants me to be. The line isn't clear to me, and I'm scared of it.