You have the option to throw him out of the party or kill him. Get over it, or don't play the game. This is a game, a narrative art. You are not forced to play it. You don't go around protesting that Romeo and Juliet should be prohibited due to suicide triggers, you just simply should avoid it.
I personally like the NPC because he is a creep, and it is interesting. Interesting to interact with it, to kill him, to throw him out, or even to get to know him. As I presume he will turn at to be a character with more layers. He is a slave to his master, an undead after who knows how many years of suffering and abuse. I can't wait to see his struggle with his nature, his two fold curse. I presume there might be interesting character development on his part during the game. Scratching that because you find it disturbing is not a solution, because with that attitude we could burn all games, movies, books and really any piece of art. If you can't cope with it you should either avoid it or look for professional help, because the purpose of art is to trigger emotions, to make you think... If you can't cope with such a small thing it is not healthy and avoiding it and ignoring it might be a temporary solution for you, but trying to force your avoidance on others definitely not the way.
I completely agree.
