Apathy

Apathetic Aura. The Apathy emanates an aura that gradually erodes the willpower of those within its reach. The Apathetic Aura extends in a 500-feet radius. When a creature first enters the aura, it must make a DC 13 Wisdom saving throw. On a failed save, the creature suffers 1 level of exhaustion and gains the flaw "I'm so tired, I would prefer not to do anything" if they dont already have it. A creature can only be affected by this aura once per day, and the flaw dissipates when its level of exhaustion reaches 0. On a successful save the creature is immune to all Apathetic Auras until the next dawn. Finishing a long rest within the Apathetic Aura doesn't reduce a creature's exhaustion.

Pack Enhancement. The Apathy gains the following benefits when it is within 20 feet of another Apathy:

• The range of the Despairing Wail action becomes 60 feet, and the DC increases by 1 for every other Apathy within 20 feet of it to a maximum of DC 23.
• The radius of the Apathetic Aura increases to 1000 feet, and the DC increases by 1 for every apathy within 20 feet of it to a maximum of DC 23.
• The DC for the Weariness reaction increases by 1 for every apathy within 20 feet of it to a maximum of DC 23
• The Apathy has advantage on all saving throws against spells and magical effects.
• When an Apathy succeeds on its Undead Fortitude saving throw, it gains temporary hit points equal to half the damage it would have taken.
• When 5 Apathy takes the Despairing Wail action on their turn each creature in 60ft must make a DC 17 Wisdom Saving throw. On a failed save the creature suffers 1 level of exhaustion and gains the flaw "I'm so tired, I would prefer not to do anything" if they dont already have it. The DC for this increases by 1 for every additional Apathy that takes the Desparing Wail action to a maximum of DC 23.

Silver Weakness. In addition to it's vulnerability to radiant damage, the apathy is also vulnerable to attacks from silvered weapons.

Undead Fortitude.  If damage reduces The Apathy to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant, from a silvered weapon, or from a critical hit. On a success, The Apathy drops to 1 hit point instead.

Claws. Melee Weapon Attack: +3 to hit, reach 10ft, one target. Hit: 6 (2d4+1) slashing damage. 

Despairing Wail (Recharge 5-6). The Apathy emits a bone-chilling wail in a 30-foot radius sphere. Each creature in the area must make a DC 13 Constitution saving throw. On a failed save, the creature's hit point maximum is reduced by 1d4. This reduction lasts until the creature finishes a long rest. If this effect reduces a creature's hit point maximum to 0, the creature dies.

Weariness: When a creature hits the Apathy with a non-magical melee weapon attack that isn't silvered, it can use its reaction to force the attacker to make a DC 13 Wisdom saving throw. On a failed save the attacker's movement speed is halved until the start of the end of their next turn and the attacker's next melee attack deals half damage on a hit.