Flanker

With your skill in combat and your ability to coordinate well with those who fight at your side, you gain the following benefits:

• While you and at least one allied creature are on opposite sides of a hostile create and are in melee range you gain advantage on your attack rolls against the flanked creature.
• When you hit with an attack that is benefitting from the advantage offered by flanking one ally may choose to spend their reaction to make an attack of opportunity.