Most Castlevania games have a more realistic look to them, well the people do anyway(Maybe not for those giant portraits they use while they talk). To show some emotion in the face of your character, you'd either have to make him pretty big or disproportional, if you want to stick to a smaller more proportional look, I would suggest trying to show emotion throughout the entire body, aka body language(I think). For me personally, I think you should go with a more realistic style.