As far as anime vampires go, you probably expect something a little more bad ass than this.

Mosquiton here is a bit scrawny, there's barely any meat on him, he has to be coaxed into doing the crazy things his master wants, he also looks kinda dorky with sunglasses he barely wears, even when he goes full berserk vampire, the demon like bloodlust eyes are the only difference and even then he has a habit of being Thanos snapped everytime he goes full bersek mode, not made any easier when his servants are a fire demon and a snow woman that are arguably more useful than Mosquiton is, the dub even makes fun of his name sounding like Mosquito.
So does this character have any saving grace? He has moments in the TV series and Manga where he does look the part so he's not a complete lost cause.
When other vampires in the same anime group include Dio Brando, Hellsing's Alucard and Castlevania's Alucard, it's hard to reach an already high bar in design.