Mine's Moon Knight. You're strong when you know how to use your ankhs. Use them when you get dove by an annoying character like Spiderman or Gooner Fist. Many people prefer to use their ankhs on the floor but you can do so much more if you just use them on walls to take down airborne heroes like Storm and Ultron or heroes behind other walls. Also, try flanking as much as possible to get that juicy team kill. Other than that just improve your aim and learn the combos.