Argus

Abnormal Vitality. If damage reduces the Argus to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the Argus drops to 1 hit point instead.

Horrifying Visage. Each creature within 60 feet of the Argus that can see it must succeed on a DC 13 Wisdom saving throw or be frightened for 1 minute. A frightened target can repeat the saving throw at the end of each of its turns, with disadvantage if the Argus is within line of sight, ending the effect on itself on a success. If a target's saving throw is successful or the effect ends for it, the target is immune to the Argus' Horrifying Visage for the next 24 hours.

Abnormal Sight. The Argus is immune to any sneak attacks or related type abilities. It can see in every direction, and has advantage when it uses the dodge action. 

Vigilance. The Argus is immune to being surprised.

Deaf. The Argus cannot hear, and therefor fails any Hearing-Based tests. 

Corrupting Touch. Melee Spell Attack: +4 to hit, reach 5 ft., one target. Hit: 12 (3d6 + 2) necrotic damage.

Psyonics:

• Horrific Gaze: This targets one creature, the creature must make a  DC 17 WIS Saving Throw. On a failure, the creature takes 1d6 Psychic damage and is frightened. An Argus likes to use this attack against warriors and other powerful creatures early in a fight, to break up the opposition.
• Rotting Eye: The targeted creature must make a DC 16 Constitution saving throw, taking 12 (4d6) necrotic damage on a failed save, or half as much damage on a successful one.
• Evil Eye: When the Argus uses Evil Eye on a creature it can see, the Argus gains Advantage on any attacks made against the creature, and also has advantage on saving throws and skill checks caused by the actions of that creature. 
• Telekinetic Shift: If the target is a creature the Argus can see. It must succeed on a DC 16 Strength saving throw or the Argus moves it up to 30 feet in any direction. It is restrained by the Argus' telekinetic grip until the start of the Argus' next turn or until the Argus is incapacitated. 
• Unnatural Insight: The Argus looks into the mind of a single creature it can see with an intelligence of more than 4. It learns rudimentary knowledge about this creature, and also it's ability scores. If the Argus has used this ability on a creature before, when it uses it again it will learn private information and secrets about that creature. 
• Thrall (Recharge 5/6): The Argus reaches into the mind of a creature it can see. That creature must make a DC 15 WIS Saving Throw or be Dominated by the Argus for the next 3 rounds. During this time the Argus commands the creature's actions. Every round the creature may make a DC 17 WIS Check to attempt to end the effect early. 
• Mind Sapping: The Argus saps life from a creature it can see and who is conscious. This attack does 2d8 Psychic damage to the creature and adds an amount equal to the damage to the Argus' health. This amount cannot exceed either an amount that would lower the creatures Hit Points to or below Zero or an amount that would increase the Argus' Hit Point above it's maximum.