Leadership gives bonuses to party members and friendly NPCs that can see the individual character(s) with Leadership. It doesn't affect the character that the aura originates from, but they can receive the bonus from other characters with Leadership. The effects do not stack with multiple leaders. When hovering over the Leadership ability, the tooltip claims level 4 and above Leadership gives a bonus to armour. This is a 10% bonus that is not listed in the Status Effect, but can be found in the Armour info in the inventory. Leadership gains a +1 bonus from the Righteous trait.