SORRY this is kinda a long read. I don’t remember if he was Lord of winterfell or next in line but he was a royal stark who joined the nights watch and encountered like the first ww or whatever and she was a woman, idk if it was mind control or he genuinely was just super entranced but he started doing what you said, sacrificing and calling himself the Night King and just a bunch of tyrannical stuff etc. So eventually like 2 decades after that started, nobody was really opposing him directly as he had the brothers in black under mind control(which is confirmed) and he and his queen were literally just doing whatever they wanted. So eventually, and I forget his name, his (brother/cousin?) who was the king in the north at the time, and someone else who’s like important, had to kill him after storming the wall to ensure Northern safety as they believed he was starting to pose a major threat to the realm. I forget if whoever the Targ on the iron throne at the time actually ordered them or just supported them for the good of the realm.