Complex sentence: The series gradually evolved into a state where Manolito and Buck were the principal stars of the show, and its most popular characters, as they were the ones who tended to get into trouble, since both were completely irresponsible, particularly under the influence of drink.
Split into simpler sentences: The series gradually evolved into a state where Manolito and Buck were the principal stars of the show. They became its most popular characters, as they were the ones who tended to get into trouble, since both were completely irresponsible, particularly under the influence of drink.