Nowaru

Stealth
Check: +50% Agility against the target's Perception.
Stealth attack deals double damage. (1)

Assassination
Penalties to the target in the gray vision zone increase to 60%, and to 100% in the red zone.
Melee: attacks made directly from behind deal five times the damage.
Ranged: attacks made from the red vision zone deal two and a half times more damage. (2)

Two-handed weapon
Two-handed weapon proficiency
The penalty for using a one-handed weapon is negated. (1)

Polearm
Two-handed weapon proficiency
The penalty for using a polearm is negated. (1)

Accurate Shot
Perception - 15 = chance to paralyze the opponent with each shot. -10 for medium armor and -20 for heavy armor. (1)

Bullseye
Perception - 20 = chance to instantly kill the opponent.
Reload: 5 turns (Intelligence = 10), 4 turns (Intelligence = 20), 3 turns (Intelligence = 30), 2 turns (Intelligence = 40), 1 turn (Intelligence = 50) (1)

+3 to all characteristics.

Is this some kind of passive ability?

Does it stack with this:

It's a minor detail, but anyway.

Does it work with firearms?

Hmm, and what characteristics does initiative depend on? I can't figure it out.

Let's say, if I don't need magic, can I reallocate three points from it to, say, agility?

Origin Bonus: artifact.

Doesn't anyone have any more questions?