Brigand Captain

Indomitable (2/Day). The Brigand Captain rerolls a failed saving throw.

Brute. A melee weapon deals one extra die of its damage when the Brigand Captain hits with it (included in the attack).

Action Surge: Once per day, the Brigand Captain can take 1 additional action on his turn. 

Multiattack. The Brigand Captain makes three Trident attacks.

Trident (of Warning). Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 12 (2d6 + 5) piercing damage, plus 7 (2d6) Trident damage if the champion has more than half of its total hit points remaining.

This magic weapon warns you of danger. While the weapon is on your person, you have advantage on initiative rolls. In addition, you and any of your companions within 30 feet of you can’t be surprised, except when incapacitated by something other than nonmagical sleep. The weapon magically awakens you and your companions within range if any of you are sleeping naturally when combat begins.

Notes: Advantage: Initiative, Damage, Detection, Combat

Second Wind (Recharges after a Short or Long Rest). The champion regains 20 hit points.

Opportunity Attack. Melee Weapon Attack:  +9 to hit, reach 10 ft., one target. Hit: 12 (2d6 + 5) piercing damage, plus 7 (2d6) Trident damage if the champion has more than half of its total hit points remaining. Other creatures provoke an opportunity attack from him when they enter his reach.  A creature hit by this attack has its speed reduced to 0 for the rest of its turn.