Carol: Aim for the Head
Your survivors' attacks are more likely to be Critical Hits.  The percentage improvement of the likelihood of a critical hit is dependent on the level of Carol’s Aim for the Head; the higher the level the greater the chance of a critical hit.

Gabriel: Mysterious Ways
Your survivors are more likely to dodge melee attacks and have their traits activate.  The percentage chance of a dodge or trait activation is dependent on the level of Gabriel’s Mysterious Ways; the higher the level the greater the chance of a dodge and ability activation.