Yeah, vindictiveness born out of abusive childhoods, poor upbringing they attempt to rise out of by talent and cunning, return to and stay in their childhood homes though, vengefullness and eternal hatred for those who wronged them as a kid, hypnotizing black eyes, a life long passion for their childhood friend, who died young leaving behind a baby, who has it's mother's eyes(which is mentioned over and over again), a complicated relationship with this kid that is resolved into happiness and forgiveness after their death.

You know, just some random, superficial traits, that are hardly that important for Snape or Heathcliff.