Sight: Blind

Evasion. If the Abyssal Monk Titan  is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails

Multiattack. The Abyssal Monk Titan makes three attacks with its fists

Unarmed Strike. Melee Weapon Attack: +10 to hit, reach 10 ft., one target.
Hit: (3d6 + 7) bludgeoning damage. If the target is a creature, it must succeed on a DC 12 Constitution saving throw or be stunned until the end of the Titan's next turn.

Corrupting Touch.
When the Abyssal Monk Titan hits with a melee attack, the target must succeed on a DC 14 Constitution saving throw or be cursed with abyssal corruption. The cursed target takes an additional (1d8) necrotic damage at the start of each of its turns. The curse lasts until the Abyssal Monk Titan is defeated or Remove Curse spell is used.

Crushing Grasp. When the Abyssal Monk Titan successfully grapples a creature (escape DC 18), it can immediately crush the target as part of the grapple attempt, dealing 14 (4d6) bludgeoning damage. While the target remains grappled, the Abyssal Monk Titan can use one or more of its attacks on its turn to deal 14 (4d6) bludgeoning damage as it tightens its grip.

Soul Rend (Recharge 2).
The Abyssal Monk reaches out with its clawed hand, attempting to tear the very soul from a creature it can see within 5 feet. The target must make a DC 16 Wisdom saving throw. On a failed save, the target takes (1d8) necrotic damage and is paralyzed until the end of its next turn. On a successful save, the target takes half as much damage and is not paralyzed.

Shadow Step. Briefly surrounded by swirling black mist, Abyssal Monk Titan  teleport up to 30 feet to an unoccupied space that is aware of, disappearing into the shadows and reemerging in silence.

Riposte (Recharge 5–6).
When a creature misses the Abyssal Monk Titan with a melee attack, the Titan can use its reaction to make a melee weapon attack against the attacker.
Melee Weapon Attack: +10 to hit, reach 10 ft., one target.
Hit: (3d6 + 7) bludgeoning damage plus (2d6) necrotic damage.

Deft Parry.
When the Abyssal Monk Titan is hit by a melee attack, it can use its reaction to add +4 to its AC for that attack, potentially causing the attack to miss.