Highlighted weapons are free options.
Nicole is a potent Support that provides both a shield and a sizeable Flat ATK buff to the entire team. The party member on field also gets an additional ATK buff after 3 seconds or instantly if they are a Hexerei character.
Nicole needs 4000 Attack to reach her full Attack buff.
Nicole's Burst provides additional damage that counts as being dealt by the triggering character, not Nicole herself. This damage matches the elemental type of the triggering character but does not apply the element at all.
Some teams do not gain a lot - if anything at all - from Nicole's Burst, in which case building Energy Recharge is not required.