2 items: Adds 657 Critical Chance
3 items: Gain Minor Slayer at all times, increasing your damage done to Dungeon, Trial, and Arena Monsters by 5%.
4 items: Adds 1487 Offensive Penetration
5 items: Increases your damage done against monsters by 7%. When you interrupt an enemy, you increase your damage done against monsters by an additional 7% for 10 seconds.