Mechanical Mind. Due to his warforged nature he cannot be put to sleep by magical means. He has advantage on saves to resist to being charmed but disadvantage to Wisdom checks for illusions.

Precision Movements. He may get up from being prone by spending 5 feet of movement speed instead of half. While rising from prone the Abyss Watcher may make a dagger or sword attack at disadvantage to all enemies within 5 feet of him.

Escape Artist. He may use an action to automatically escape from any grapple or restrained condition.

Blood Rite. If health is below 50%, may sacrifice 1 turn and become empowered, all attack ranges increase by 5 feet (except flying strike AOE) and gain 1d6 fire damage. If hit must make CON save or end Blood Rite early. At start of next turn if Blood Rite was not ended early Abyss Hunter regains 5 hit dice.

Multiattack. The Abyss Hunter takes 2 actions per turn, if their first action is a Greatsword attack they may follow up with a Greatsword, Dagger, or Wide Swing attack. If their first action is a Leap they may follow up with a Lunge or Flying Strike attack. Otherwise they only take one action.

Leap. The Abyss Hunter leaps 15 feet into the air and moves 30 feet backwards. This action does not provoke attacks of opportunity.

Greatsword. Melee Weapon Attack: +10 to hit, reach 10 ft., 1 target. Hit: 15 (2d8 + 6) [Slashing] damage. Empowered: +10 to hit, reach 15 ft., 1 target. Hit: +3 (1d6) [Fire] damage

Dagger. Melee Weapon Attack: +8 to hit, reach 5 ft., 1 target. Hit: 8 (1d8 + 4) [Pirecing] damage. On a successful hit the target must make a 16 strength con save or have either their weapons shield disarmed.

Wide Swing. Cone AOE all targets within a 10 ft. Cone must make a DC 16 Dex save or suffer: 14 (1d12 + 8) on a failed save and half on a successful save. Empowered: +10 to hit, 15 ft cone. Hit: +3 (1d6) [Fire] damage.

Lunge. Line AOE all targets within a 25 ft. Line must make a DC 16 Dex save or suffer: 14 (1d12 +8 ) on a failed save and half on a successful save. The Abyss Hunter moves 25 ft in the direction of the attack. Empowered: +10 to hit, 30 ft line. Hit: +3 (1d6) [Fire] damage.

Flying Strike. All targets within a 15 ft. x 15 ft. AOE must succeed a Dex save or suffer 16 (1d20 + 6) force damage on a failed save or half on a successful save. The Abyss Hunter leaps 15 ft. into the air and lands on any open spot within 30 ft with the Greatsword and creates a shockwave. Empowered: +10 to hit, 15 ft x 15 ft AOE. Hit: +3 (1d6) [Fire] damage.

Heavy Crossbow. Ranged Weapon Attack: +8 to hit, range 100/400 ft., 1 target. Hit: 8 (1d10 + 3) [piercing] damage.

Parry. As a reaction to a melee attack the Abyss Hunter may reduse the damage of an incoming attack by 1d12 of damage. If all damage was prevented this way the attacked is stunned until their next turn. 

1 Legendary Action per combat.

Mechanical Companion (Costs 1 Actions). At start of its turn the Abyss Hunter calls for their Wolf Construct. The Wolf Construct joins the combat in 5 - 1d4 turns.