Yeah, and the shock, surprise and frankly the embarrassment that a mighty vampire lord would experience when shitting himself makes him miss a turn, also he probably becomes more vulnerable. If not physically then definitely emotionally.

I guess this would add some additional damage? Just imagine the horror of this happening for the first time in hundreds maybe thousands of years. There's nothing in you, that could actually provided the necessary.. "material". So where does it come from? And then the realization sets in: you're not alone. The fear, the feeling, the smell, the audience. This could kill someone! (⁠٥・⁠_⁠・⁠)

Imagine the emotional and physical damage of taking your first shit in thousands of years.