You know other harem with similar MC?
Most harem that I have read only have pathetic MC who kept rejecting women's advances.
Here, he wants all the girls. Unfortunately he's a scumbag because he kept toying with the elf feeling about her desire to be monogamous. It would be better if he opens up about his desire for harem.
And I personally don't see which part of him is considered as protagonist syndrome. He genuinely tried to kill the progenitor vampire at first, which isn't very protagonist like.