Balancer

 Magic Resistance. The balancer has advantage on saving throws against spells and other magical effects. 

Legendary Resistance (1/day). If the balancer fails a saving throw, it can choose to succeed instead.

Multiattack. The balancer makes two attacks with it's Divine Weapon

Divine Weapon. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 20 (3d10 + 3) radiant damage. Creatures hit with this attack must succeed on a DC 19 Constitution saving throw or have all spell effects affecting them ended.

Divine Spear Formation. The balancer causes magical spears to rise from the ground in a 40 foot line in front of it. Creatures must make a DC 17 Dexterity saving throw, taking 23 (5d8) radiant damage on a failed saving throw, and half as much on a successful saving throw. 

Harmony of the Scale (Recharge 5-6). The balancer lets out a celestial harmony that compels up to six creatures within 60 feet of the balancer to attack the closest creature to them. The creatures must succeed a DC 19 Charisma saving throw or be Charmed for 1 minute, and forced to fight the closest creature to them. An affected creature cannot attack the balancer.

Celestial Step (Recharge 4-6). The balancer teleports up to 30 feet to a point it can see with everything I is wearing or carrying.

Divine Spear Defense. In response to taking damage the balancer causes magical spears to erupt in a 5 foot radius around it. Creatures in that area must make a DC 17 Dexterity saving throw, taking 23 (5d8) radiant damage on a failed saving throw, and half as much damage on a successful saving throw.