Auras are skills available to paladins that provide a bonus to all nearby party members, including the paladin himself. They are cast instantly, cost no mana, and have unlimited duration. However, you can only have one aura active at a time, and each character can only be affected by one aura at a time per paladin in the party. If you are in a party with another paladin, you will want to coordinate so the two of you are using different auras.