Overwatch

After expert training with firearms, the bearer of this fear can make defensive attacks against combatants at range, who are attacking an ally of theirs; and gains expertise in perception.
-You gain expertise in perception.
-When an ally 30 or more feet away from you is hit with a melee attack, you can use your reaction to immediately make a ranged weapon attack against your allies aggressor. On a successful hit made by this feature, any remaining attacks on the aggressor's turn are made at disadvantage.