Just like all of the other types of Castle Wars armour, using just one or two pieces of the armour gives a damage bonus. The damage bonus works as follows: Any one piece gives +8% damage, two give +14%, and the set gives 20%. This would take approximately 625 hours (~24 days) to obtain the full set, and 416.7 hours (~17 days) to obtain just the platebody, platelegs and shield, assuming you won every game.