For the Batman and Joker drawing I used 2H, HB, 2B and 4B; I´ve seen your work and you definetly got talent (that Joker IS amazing) I was worried about the shadows too when I started using B pencils, because I didnt want to ruin it by putting a lot of dark, but trust me on this one, the darker it is, the cooler (and more realistic) it looks. You just have to do it slowly so the drawing doesnt end up being a plain black silhoutte (it happened to me once haha)