It started in the demon ruins. Up to that point I had been invaded occassionally, been killed, and then moved on. I never had much trouble finding help for bosses and getting to the boss before an invader could reach me, but that changed as I was coming up on the firesage demon. I think it was five times in a row that I became human and the same invader showed up and crushed me. I tried all kinds of tactics hiding in different spots to surprise, changing gear, etc. but nothing worked. It was tremendously frustrating burning through my humanity and each time hoping for a summon sign to show up prior to the invasion by the Darkwraith. It was then wash, rinse, repeat with the centipede demon, a constant stream of invaders. Every time I would consume a humanity and reverse hollowing the clock was ticking. It made for a lot of stressfull moments...
So, in the end, my simple mind demanded revenge and I became a darkmoon. I still am not good at PVP but have started to win some fights and maybe will some day feel that I have erased the scars that the darkwraiths have left on me. No surpise I spend a good deal of time using the blue orb in the demon ruins...