Confidence is a bushido special. It gives you a massive HP regen until you take damage again. Using it you can regen all your HP is a few seconds... as long as you don't get hit.
Archers tend to run away from anything that can hit them while their HP's come back. Dexxers with parry have a better chance of avoiding damage and don't have to back off to regen.
Bushido skill takes the place of a shield for a samouri. A samouri parrys with his/her weapon instead of a shield.
Bushido actually gives a shield a parry penalty making it not worth carrying a shield for defense.