Role aptitudes
Agility, Ballistic Skill or Weapon Skill, Fieldcraft, Finesse, Perception
Role talent
Jaded or Leap Up
Role bonus
Sure Kill: In addition to the normal uses of Fate points (see page 293), when an Assassin successfully hits with an attack, he may spend a Fate point to inflict additional damage equal to his degrees of success on the attack roll on the first hit the attack inflicts.
Ignis Aeternus WH 40K campaign notes 